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O J Degrossi

Publications and source records attributed to O J Degrossi.

At least 19 recordsLinked to original sources
PubMed1996

[Tc-99-sestamibi scan in the preoperative localization of abnormal hyperfunctioning parathyroid glands].

Hyperparathyroidism is a relatively frequent condition mostly due to a solitary parathyroid adenoma. Although it has been claimed that surgical exploration is the best way to visualize the abnormal parathyroid gland, several imaging techniques have been proposed to localize it in order to simplify and shorten the surgical procedure. Echography, thalium-technetium scintigraphy, computerized tomography and nuclear magnetic resonance have shown a mean sensitivity of 75% which can be increased to about 90% by combining 2 or more of these procedures. In this study, we evaluated the utility of Tc-99m-sestamibi scintigraphy in 13 patients with hyperparathyroidism (11 primary, 2 secondary). High resolution neck echography was carried out in all of the cases. Cervical scans were obtained 10-15 min and 3 hours after giving an i.v. injection of 25 mCi Tc-99m-sestamibi in all the patients; suppression studies with combined 131-I were also done. Positive scans were obtained in 11 out of the 13 patients. Abnormal parathyroid glands were found and surgically excised in all the cases (10 adenomas, 1 carcinoma, 2 hyperplasias). Echographic localization had a sensitivity of only 33.3%. On the contrary, Tc-99m-sestamibi showed a sensitivity of 56% for the whole group, increasing to 82% in the 11 patients with primary hyperparathyroidism whereas the positive predictive value was of 91% and 90%, respectively. We conclude that Tc-99m-sestamibi is a very useful tool in localizing abnormal parathyroid glands and should be the first choice before reoperation after surgical failure or before the first parathyroid surgery whenever it is desired to shorten the surgical and anesthetic duration.

Adenoma↗
PubMed1995

Serum kinetics, bioavailability and bone scanning of 99mTc-labelled sodium olpadronate in patients with different rates of bone turnover.

The activity of olpadronate labelled with technetium-99m(99mTc) was monitored in plasma and urine samples after single oral (925 MBq 99mTc/10 mg, coadministered with 50 mg cold drug) and intravenous (925 MBq 99mTc/5 mg) administrations to two groups of patients with different rates of bone turnover. The first group comprised high bone turnover (HBTO) patients suffering from Paget's bone disease; the second group comprised patients with normal to low bone turnover (NBTO) having the diagnosis of rheumatoid arthritis and secondary osteoporosis. Kinetic variables were correlated with anthropomorphometric variables, biological markers of bone metabolism and plasma proteins. Data were also obtained after repeatedly dosing the HBTO patients. Additionally, Paget's bone and healthy bone (PB/HB) uptake before and after low-dose oral treatment were assessed by means of scintigraphy. Results showed that most of the kinetic variables did not differ between the two groups of patients, except for a greater Vss and smaller blood area under the curve AUC in the patients with HBTO. After a repeated-dose administration period, the blood AUC activity and Whole Body Retention (WBR) of the HBTO patients tended to be similar to those of the NBTO patients. In both groups, after oral dosing, the Cmax was 20 times lower than the C0.5 after i.v. injection, and the oral bioavailability ranged from 3% to 4%. Finally, the plasma t1/2 beta ranged from 9 to 14 h. Correlation coefficients were obtained from multiple regression analysis; kinetic variables showed very low correlations with anthropomorphometric measurements. In contrast the Vss and WBR were significantly correlated with serum alkaline phosphatase levels and the Vss also with urine hydroxyproline levels. Plasma protein concentration was also correlated with excretion parameters such as CLP and plasma t1/2 beta after an oral dose. Scintigraphic studies in the HBTO group allowed bone selectivity to be seen through skeletal drug uptake. The 15 Pagetic lesions analysed in the HBTO group showed a decrease in PB/HB ratio from 3.8 in the basal study to 2.7 after olpadronate administration for 30 days at the rate of 50 mg/day. In conclusion, the kinetic profile of 99mTc-labelled olpadronate, mainly AUC and WBR, showed a dependence upon bone metabolism and seemed unrelated to body size variables. HBTO patients showed a lower blood AUC but a higher Vss. Both variables may have been reflecting the fact that the drug binds selectively with calcified tissues and, in turn, with the target compartment. Scintigraphy confirmed the labelled-compound bone selectivity as a desirable feature for a bone-scanning agent.

Administration, Oral↗
PubMed1991

[Serum thyroglobulin and whole-body scanning as markers in the follow-up of differentiated thyroid carcinomas].

We have compared two "markers" in the follow up of post treatment (surgery and therapeutical use of I-131) differentiated thyroid carcinoma. In 153 patients, thyroglobulin (Tg) serum levels were measured after withdrawal of I-thyroxine therapy, before performing a whole-body scan (WBS) with iodine-131; in 55 of these patients, Tg was measured again after at least 45 days of I-thyroxine treatment. The patients were followed between 3 and 10 years, and there were 2713 matched studies. Our results indicate for both parameters, false positive and negative values; sensitivity (SE) for WBS was 89% and specificity (SP) 83%; Tg presents a SE of 86% and SP of 83%. Matching both parameters, SE was 95% and SP 98%. The causes of false results are discussed. Tg determinations under I-thyroxine treatment do not permit the establishment of absence of illness; 37.7% of patients with demonstrated metastases or relapse showed negative Tg values that reached pathological values after suspension of I-thyroxine treatment; another 41.4% with elevated Tg values under therapy reached these values after suspension of I-thyroxine. Both markers, when utilized at the same time, offer the best possibilities in the follow-up of differentiated thyroid carcinoma, when determinations are carried out after suspension of hormonal treatment.

Adenocarcinoma↗
PubMed1985

Technetium-99m APD compared with technetium-99m MDP as a bone scanning agent.

We have investigated the possibilities of technetium-99m-(-3-aminohydroxypropylidene)-1-1-bisphosphon ate ([99mTc]APD) as a bone scanning agent in 14 normal subjects and 28 patients. Similar studies in the same normal subjects and patients were carried out with 99mTc-methylene-bisphosphonate ([99mTc]MDP). The compounds were labeled with 99mTc by means of an electrolytical method; the free pertechnetate content was always under 1%. The [99mTc]APD T1/2 of the third component of the disappearance plasma curve in six normal subjects was 152 +/- 46 min (mean +/- s.d.), while the 24-hr whole-body retention (WBR) was 17.6% +/- 4.6. The [99mTc]MDP value of the 24-hr WBR was 28.6% +/- 3.9 (p less than 0.001). The bone/soft-tissue ratio (B/ST) was investigated in eight control subjects on the eleventh thoracic and the fourth lumbar vertebrae. The B/ST ratios were similar for both APD and MDP studies. In 28 patients with suspected bone metastasis or primary bone disease, bone scintigraphy was carried out; both compounds showed similar findings and the same number of positive results. In five of these patients, the lesion/normal bone ratio was determined with values of 4.6 +/- 2.0 in APD studies and 4.8 +/- 2.3 with MDP. APD was also used in 126 patients; no adverse reactions were observed. The APD dose used i.v. for bone scanning was 200-fold less than those employed by mouth per day, for the treatment of bone disease for long periods. In our experience, APD appears to be an adequate agent for bone scintigraphy.

Adolescent↗
PubMed1980

Congenital goitre due to "thyroid peroxidase-iodinase defect".

A 16-year-old male cretin with congenital goitrous hypothyroidism and 95% discharge in the perchlorate test underwent thyroidectomy. Thyroid studies disclosed negligible peroxidase (TPO) activity in the tyrosine iodinase assay, 6 nmoles I- inc./g (normals: 220-410). Using the same particulate preparations, a high activity was obtained in the guaiacol assay, 485 U/mg vs. 176 U/mg of a control gland. Goitre TPO was solubilized by treating the thyroid pellets with deoxycholate, trypsin and acetone. Soluble goitre TPO was further purified on Sephadex G-200. By this procedure we obtained a single peak of enzyme activity for oxidizing guaiacol, although no activity was found for iodinating tyrosine. I2 formation, as measured by the triiodide assay, was only 28% of that expected for normal TPO when compared for guaiacol oxidation. It is concluded that this abnormal TPO was the cause of the congenital hypothyroidism of the patient. We suggest the term "thyroid peroxidase-iodinase defect" for defining this newly found inborn error.

Adolescent↗