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Biomedical subjects

G Agnese

Publications and source records attributed to G Agnese.

At least 19 recordsLinked to original sources
PubMed2003

Thallium-201 myocardial scintigraphy in patients with Wolff-Parkinson-White syndrome.

Wolff-Parkinson-White syndrome (WPW) is known to cause abnormal rest electrocardiogram and stress test. Thallium-201 myocardial scintigraphy has been particularly indicated for the noninvasive evaluation of coronary artery disease in these patients. The study group consisted of 11 WPW patients with abnormal ST-segment depression at rest electrocardiogram and/or stress test, with the absence of signs or symptoms of coronary artery disease. All the patients underwent exercise thallium-201 imaging associated with stress test by bicycle ergometer: 7 of them had ST-segment depression, but without other signs or symptoms of coronary artery disease. Transient and moderate myocardial perfusion defects were found in 5 of 11 patients. Perfusion defects in patients with WPW could derive from dyssynergy of ventricular activation, which could modify myocardial perfusion scintigraphy despite the absence of angiographic coronary stenosis. Previous reports and our data concluded that transient perfusion defects during exercise thallium-201 testing in WPW patients without cardiovascular disease may be observed. Thus, thallium-201 myocardial scintigraphy could present some limitations as a helpful adjunctive method for assessment of coronary artery disease in WPW patients.

Adult↗
PubMed2001

Technetium-99m-sestamibi scintigraphy in multiple myeloma and related gammopathies: a useful tool for the identification and follow-up of myeloma bone disease.

BACKGROUND AND OBJECTIVES: Technetium-99m 2-methoxy-isobutyl-isonitrile ((99m)Tc-sestamibi) has recently been proposed as a potential tracer in patients with multiple myeloma (MM), as its increased uptake in the bone marrow has been reported as indicator of myeloma activity. We evaluated the role of (99m)Tc-sestamibi scintigraphy in the detection of myeloma bone disease in MM and related gammopathies, and also assessed its relationship with clinical status and stage of the disease, focusing in particular on the early follow-up of a small series of MM patients treated with high-dose therapy. DESIGN AND METHODS: Forty-six consecutive patients affected by MM or monoclonal gammopathy of undefined significance (MGUS) were studied by whole body scans obtained 20 minutes after administration of 740 MBq of (99m)Tc-sestamibi. A semiquantitative uptake score was used and scintigraphic findings were correlated with clinical and laboratory data. RESULTS: All the MGUS patients showed a negative (99m)Tc-sestamibi scan. Among the 32 MM patients (25 with active disease and 7 in clinical remission) 24 showed a positive scan, while 8 presented only a physiologic uptake of the tracer. The uptake score correlated significantly with all the most relevant clinical variables. In the follow-up of 8 MM patients treated with high-dose chemotherapy (99m)Tc-sestamibi closely paralleled the activity of myeloma bone disease. Comparison with X-ray skeletal survey showed discordant results in 14 out of the overall 56 scans obtained (27%), with 10 cases of negative (99m)Tc-sestamibi scans but lytic bone lesions revealed by X-ray (7 of them were in clinical remission), and 4 negative X-ray surveys in patients with positive (99m)Tc-sestamibi scans. Overall sensitivity and specificity of (99m)Tc-sestamibi scintigraphy in detecting myeloma bone disease were 90% and 88%, respectively. INTERPRETATION AND CONCLUSIONS: This study provides additional evidence indicating that (99m)Tc-sestamibi scintigraphy closely reflects myeloma disease activity in bone marrow, with very high sensitivity and specificity. (99m)Tc-sestamibi scintigraphy is therefore suggested as a reliable new tool for the staging and follow-up of myeloma bone disease.

Adult↗
PubMed2000

Pattern of lymphatic drainage to the sentinel lymph node in breast cancer patients.

BACKGROUND AND OBJECTIVE: We performed a pilot study on 30 consecutive patients undergoing sentinel node (sN) biopsy by radioguided surgery and vital blue dye mapping to determine whether there is a single sN for each breast independent of tumor site or an sN specifically related to the site of the breast neoplasm. METHODS: There were 6 groups of 5 patients; each patient had a subdermal injection of radiotracer on the tumor site plus a second injection of radiotracer that was changed in every subset of patients to test whether modifying the site or the route of injection could have impaired the proper detection of the sN. RESULTS: "False" sN were detected only in patients who had a second injection of radiotracer away from the tumor site; this occurred in 2 of 5 patients (40%) in group I, in 3 of 5 patients (60%) in group II, in all patients in group III, and in 3 of 5 patients (60%) in group IV. The different route of injection (peritumoral or subdermal) always on the tumor site that was tested in groups V and VI did not impair the proper detection of the sN. CONCLUSIONS: Our findings support the hypothesis of a precise topographic correspondence between the primary tumor and its specific sN more than the existence of a first sN in the axillary basin, which indiscriminately drains all quadrants of the breast, like "a neck of a bottle." This should be considered for the proper selection of the injection site of either vital blue dye or radiopharmaceuticals.

Adult↗
PubMed2000

Mapping sentinel lymph node in breast cancer by combined lymphoscintigraphy, blue-dye, and intraoperative gamma-probe.

The purpose of the present work was two-fold: 1) to evaluate the predictive value of the sentinel lymph node (sLN) versus the axillary-node status in patients with T1-T2 breast cancer, and 2) to form an experimental basis for a randomized trial in which one group of patients with non-metastatic sLN will not have axillary dissection. Of a group of 284 patients considered for this analysis, 264 had a T1 cancer (16 T1a, 37 T1b and 211 T1c), while 20 had a T2 cancer; 243 patients were in clinical stage N0 and 41 were N1. All patients underwent lymphoscintigraphy 18 hr before surgery: 10 MBq in 0.15 mL of 99mTc-human albumin nanocolloids (particle size between 50-80 nm) was injected subdermally at the cutaneous projection of the tumor. Static gamma-camera images were acquired every 10-15 minutes until scintigraphic identification of the sLN. At surgery, 1-2 mL of Patent-Blue Violet was injected subdermally, and the sLN was searched by gamma-probe and by the dye method. The surgically isolated sLN was processed for intraoperative Hematoxylin & Eosin (H&E) histology, then for delayed histological and immunohistochemical examinations. The sLN was successfully identified by the combined radioisotopic procedure and Patent-Blue dye technique in 278/284 cases (97.9%). The Patent-Blue dye technique alone identified fewer sLNs than the radioisotopic procedure alone (56.3% versus 97.2%). Analysis of the predictive value of the sLN as to the status of axillary lymph nodes was limited to 197 patients undergoing standard axillary dissection irrespective of the sLN status. Overall, 63/191 (33%) identified sLNs were metastatic, the sLN alone being involved in 37/63 (58.7%) patients; a positive axilla status with negative sLN was found in 10/73 patients with metastatic involvement (13.7% false-negative rate). In conclusion, subdermal lymphoscintigraphy was confirmed to be an effective technique for sLN mapping; the addition of Patent-Blue dye minimally improved intra-surgical identification of the sLN. There was a high, but not absolute, correlation between a negative sLN and a negative axilla.

Adult↗
PubMed1984

Statistical evaluation of inter- and intra-laboratory variations of the Ames test, as related to the genetic stability of Salmonella tester strains.

A statistical analysis was performed on the data resulting from an international collaborative study of the Ames test according to a standardized experimental protocol, which involved the comparative testing of 4NQO (4 doses), in 3 separate experiments for each of the 38 participating laboratories, by using a common reference (R) culture and in-house laboratory (L) cultures of 5 strains of S. typhimurium. Despite some toxicity phenomena recorded at the highest dose of 4NQO, the majority of the dose-response curves in individual laboratories were linear on a bi-log scale and their mean values fitted a linear regression framework. Scattering of data around mean values of laboratories was Gaussian-like even at the highest dose of 4NQO, toxic effects being expressed as a dose-related increase of variance. A weighted least-square analysis could therefore take into account toxic effects without resorting to a sophisticated non-linear model incompatible with log transformation. Various analytical approaches--e.g. the weighted estimates of linear regression parameters, a multifactor (laboratory, experiment, dose, culture of each strain) analysis of variance with all the possible interactions, the assessment of correlations in individual laboratories and of coefficients of variation for induced and spontaneous mutability--could detect some statistically significant differences between L and R cultures. However, at a critical evaluation on an individual basis, only few of these differences, without any peculiar involvement of given strains, were convincing in view of the existence of real phenomena of genetic drift. Therefore, on the whole, the genetic drift of Salmonella tester strains appears to lend a negligible contribution to the considerable inter- and intra-laboratory variability detected in this study. With a background variability between replications averaging 26%, a dose-related variability was evident both between experiments (28-54%) and between laboratories (44-127%).

4-Nitroquinoline-1-oxide↗
PubMed1979

[A study through factor analysis of the connection between 7 variables concerning blood lipides, with a particular reference to the interpretation of the lipidograms (author's transl)].

The AA. examined 7 variables concerning blood lipides and studied their internal relationship by means of a method, the Factor Analysis, which aims at determining the least amount of Common Factors which can sum up the information contained in the same variables. In this case three Common Factors (F) could be obtained, two of which were connected to the interpretation of the data of the lipidogram. The AA. discuss the signification of the determined Factors; they have even calculated the scores of the same Factors for each single individual and derived from the frequence distributions of the scores of F1 and F2 the normal values of the same Factors.

Autoanalysis↗
PubMed1978

[The importance of biological standardization in clinical laboratory examinations (author's transl)].

The AA. consider the various causes that can give rise to different results regarding one same biological sample which has been examined various times in the same or in different laboratories. From the analysis of the possible sources of variability and from the results obtained in research performed by various laboratories in the course of a polycentric co-ordinate study, the AA. deduce some general considerations about the measures to be taken in order to reduce the different sources of variability (either fortuitous or systematic) and they especially emphasize the practic usefulness of considering the question of "laboratory errors" not only as a question of accurate dosage, but also, and primarily, as a question of biological standardization.

Blood Chemical Analysis↗