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Biomedical subjects

G Panoutsopoulos

Publications and source records attributed to G Panoutsopoulos.

11 recordsLinked to original sources
PubMed2001

Scintigraphic evaluation of primary congenital hypothyroidism: results of the Greek screening program.

The Greek screening program for primary congenital hypothyroidism was initiated in 1979. By early 2000, thyrotropin measurements had been performed in 1,976,719 newborns, using dried blood spots obtained by heel prick. Among these children, 584 were diagnosed with congenital hypothyroidism (incidence: 1/3,384 births) and were given L-thyroxine (L-T4) replacement therapy. In order to further evaluate and classify the children as having either an aplastic (AT) or an ectopic thyroid gland (ET) or as showing thyroidal dyshormonogenesis (DN, with a nomotopic gland), scintigraphic studies were performed at the age of 2-3 years. In 413 children of this age group (including 24 subsequently diagnosed as having had transient hypothyroidism, in whom L-T4 therapy was not resumed), thyroid hormones were measured and scintigraphic studies were done after withdrawal of L-T4 replacement treatment for 3 weeks. Given the long duration of the study, we used various scintigraphic modalities. In 96 children (group A), scintigraphy was performed using technetium-99m pertechnetate (99mTcO4-; 18.5 MBq given i.v.) and a rectilinear scanner. Seventy-three children (group B) were studied with 99mTcO4- (18.5 MBq given i.v.) and a gamma camera equipped with a pinhole collimator. In these groups, atropine was administered 30 min prior to the study (0.02 mg/kg i.v. or i.m.) in order to reduce the secretion of saliva from the salivary glands. Finally, in the remaining 220 children (group C) iodine-123 sodium iodide (123I-Na) (0.74-1.85 MBq i.v.) and the same gamma camera were used. Between-group comparisons of scintigraphic findings were done with the chi square test. In 191 children from group C, thyroglobulin (Tg) was measured and in 49 children ultrasound (US) was performed (categorising the gland as AT or ET/DN). Comparison of these modalities was done with the kappa statistic. In group A, 61.5% of children had AT, 26.0% had ET and 12.5% had DN; in group B, 28.8% of children had AT, 52.0% had ET and 19.2% had DN; in group C, 23.2% of children had AT, 63.2% had ET and 13.6% had DN. Statistically significant differences in group A versus groups B and C were noted for AT and ET. The implementation of newer scintigraphic modalities, and especially the use of 123I-Na, indicates that the commonest finding in congenital hypothyroidism is ET. Scintigraphy was more concordant with Tg measurements (though at a moderate level) than with US. The latter was even less concordant with Tg values. These results show that the most appropriate approach for the evaluation and classification of congenital hypothyroidism is 123I-Na scanning.

Child, Preschool↗
PubMed2000

Transient right-to-left shunt in massive pulmonary embolism.

A 56-yr-old man, two months after an operation for an acoustic neurinoma, gradually developed dyspnea. Massive pulmonary embolism (MPE), with a significant right-to-left (R-L) shunt, was seen in a perfusion scan of the lungs with Tc-99m MAA. Radioactivity was noted in the thyroid, spleen, kidneys and brain. A cardiac ultrasound study did not reveal intracardiac shunting. A few days later, when the patient's condition improved, another perfusion scan of the lungs did not show the shunt, whereas a subsequent digital subtraction angiographic study confirmed the diagnosis of MPE but failed to reveal the cause of the shunt. In the absence of any possible pathophysiological mechanism, to explain the observed R-L shunt, we deduce that the particles of Tc-99m MAA might have passed through the precapillary pulmonary arteriovenous anastomoses and/or through dilated pulmonary capillaries, as a result of highly increased pulmonary vascular pressure due to MPE.

Angiography, Digital Subtraction↗
PubMed1999

Soluble interleukin 2 receptors' levels versus thyroid hormones levels in nonthyroidal disease.

Serum soluble interleukin-2 receptor levels, basal thyrotropin, total thyroxine, total triiodothyronine and free triodothyronine were assayed in 29--otherwise healthy--patients with pulmonary tuberculosis before initiation of anti-tuberculosis treatment and after two weeks of therapy. Twenty seven out of 29 patients presented low-normal total triiodothyronine levels, showing a statistical elevation after anti-tuberculosis therapy. Total triiodothyronine levels before anti-tuberculosis therapy were inversely correlated with levels of serum soluble interleukin-2 receptors. Further investigation on the relationship between soluble interleukin-2 receptor's levels and thyroid hormones in non-thyroidal disease can be envisaged.

Adult↗
PubMed1999

Combined protocols for myocardial perfusion imaging in patients with hypertension.

OBJECTIVE: Patients diagnosed previously with hypertension submitted to exercise testing for myocardial scintigraphy often respond with excessive elevation of the blood pressure, even when baseline blood pressure is normal, resulting in interruption of the test or false positive results for coronary artery disease. The aim of this study was to evaluate the haemodynamic changes and the safety of the combined examination protocols of dipyridamole plus handgrip exercise and of dipyridamole plus symptom-limited exercise testing on a treadmill in patients with hypertension. METHODS AND RESULTS: We performed scintigraphic myocardial single photon emission computed tomography in 240 patients with hypertension as follows: in 27 patients who were administered dipyridamole alone, in 126 patients who were administered dipyridamole and were also submitted to isometric handgrip exercise and in 87 patients who were administered dipyridamole and were also submitted to treadmill, symptom-limited exercise (modified Bruce protocol). Mean systolic blood pressure, mean diastolic blood pressure and heart rate did not rise excessively in patients submitted to exercise testing (192 +/- 18 mm Hg, 106 +/- 14 mm Hg and 111 +/- 21 bpm for the dipyridamole plus handgrip group and 180 +/- 28 mm Hg, 104 +/- 10 mm Hg and 149 +/- 19 bpm for the dipyridamole plus treadmill group, respectively), with two patients from each exercise group presenting a maximum systolic blood pressure higher than 220 mm Hg and no subsequent major cardiac complications (such as death, myocardial infarction, unstable angina or life-threatening arrhythmia). Moreover, patients in these exercise groups experienced fewer non-cardiac side effects than with dipyridamole alone, while attaining a good level of exercise stress. CONCLUSIONS: Both combined dipyridamole and exercise protocols for scintigraphic myocardial single photon emission computed tomography in patients with hypertension are safe and increase heart rate without an excessive elevation in blood pressure. Consequently, they can be recommended for clinical use. Dipyridamole combined with treadmill, symptom-limited exercise would be the first choice, with dipyridamole and isometric handgrip exercise reserved for patients with physical handicaps.

Adult↗
PubMed1998

Pulmonary tuberculosis and its therapy do not significantly affect thyroid function tests.

Basal thyrotropin, total thyroxine, total tri-iodothyronine and free tri-iodothyronine were measured in 30 HIV-negative patients with focal pulmonary tuberculosis upon starting and after one and two weeks of isoniazid, rifampicin and pyrazinamide therapy. Rapid and statistically significant elevations in free tri-iodothyronine and total tri-iodothyronine were noted after the first and second week of treatment respectively. For most patients, however, hormone levels remained within normal limits throughout the study. Overall, the effects of pulmonary tuberculosis and of its therapy on the thyroid function parameters examined, in otherwise healthy individuals, appear to be minimal.

Adult↗
PubMed1998

Thyroid function and autoimmunity in sarcoidosis: a case-control study.

AIM: To evaluate thyroid function and the presence of antithyroid autoantibodies in patients with sarcoidosis, compared to patients with chronic obstructive pulmonary disease (controls). METHODS: Sera were obtained from 26 patients (19 women and 7 men) with active sarcoidosis, age and sex matched to 26 patients with diagnosed chronic obstructive pulmonary disease. Baseline thyrotropin, total triiodothyronine and thyroxine, antithyroglobulin autoantibodies, and antithyroid peroxidase autoantibodies were analyzed. RESULTS: Only antithyroglobulin autoantibodies were significantly elevated in sarcoidosis patients (p=0.041, Wilcoxon two-sample test). CONCLUSION: Basic thyroid function parameters, with the exception of antithyroglobulin autoantibodies, were within the normal limits in patients with sarcoidosis. Their presence should be interpreted as another characteristic of a generalized immune dysfunction in sarcoidosis. Screening of thyroid disease in patients with sarcoidosis does not seem necessary.

Adult↗
PubMed1994

Comparative thrombogenicity of pacemaker leads.

To evaluate the thrombogenicity of transvenous silicone and polyurethane pacemaker leads, 9 of 12 anesthetized Yorkshire pigs (27-32 kg) were implanted with silicone (n = 5) or polyurethane (n = 4) pacemaker leads via a femoral vein. The remaining three pigs served as controls. All 12 pigs were injected with autologous indium-111 labeled platelets (300-420 muCi) 24 hours before anesthesia induction. The pigs were monitored for 3 hours under a gamma camera. Radioactivity in blood and lead segments was measured with a gamma counter. Platelet deposits were denser on silicone leads (441.58 +/- 915.0 to 2.19 +/- 2.07) than on polyurethane leads (1.21 +/- 1.33 to 0.27 +/- 0.14) (P > 0.05). Denser platelet deposits were detected at the tip of all leads. Density of platelet deposits declined from tip to distal segments in silicone leads. The percentage of injected platelet radioactivity in the lungs of pigs with either silastic leads (12.9 +/- 2.3%) of polyurethane leads (10.1 +/- 2.2%) was higher than in the controls (4.6 +/- 0.5%) (P < 0.05). This difference indicates thrombus formation and embolization in the lungs early after lead implantation. Thrombogenicity of polyurethane leads may be lower than that of silicone leads.

Animals↗