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Biomedical subjects

D Carrera

Publications and source records attributed to D Carrera.

28 records · Page 2Linked to original sources
PubMed1972

Determination of adenosine 3':5'-cyclic monophosphate in cerebral tissues by saturation analysis. Assessment of a method using a binding protein from ox muscle.

1. The Gilman (1970) procedure for determining cyclic AMP (adenosine 3':5'-cyclic monophosphate) by saturation analysis gave erroneous results when applied to the analysis of extracts of whole brain or preparations of membrane fragments from brain. 2. The extracts contained a non-diffusible factor, which enhanced the binding of cyclic AMP by the muscle protein fraction. 3. Extracts also contained material which inhibited binding, but net inhibition of binding was only observed when relatively concentrated extracts were analysed. 4. The error introduced by the factors modifying binding could be eliminated by incorporation of unlabelled internal standards in the unknowns. The design adopted enables a statistical estimate to be made of the standard error of a single assay. 5. The modified assay was used to determine bound cyclic AMP and adenylate cyclase activity in cerebral membrane fragments. Five preparations of synaptic membrane fragments contained less than 3.5pmol of cyclic AMP/mg of protein; a microsomal fraction from rat contained 65pmol of cyclic AMP/mg of protein.

Adenosine Triphosphate↗
PubMedDate not supplied

[Assessment of a neuroendocrine tumour by 111In-pentetreotid scintigraphy and PET with 18FFDOPA and 18F-FDG].

We present the case of a 67 year old patient diagnosed of a neuroendocrine carcinoid tumour of the small intestine. The tumour and subsequent metastases were resected previously by surgery, but a new recurrence was suspected. CT showed left adrenal enlargement. 18F-FDG PET was normal and 111In pentetreotide scintigraphy showed liver and left diaphragmatic uptake. 18F-FDOPA PET showed uptake foci in liver and left diaphragm and also in left adrenal gland, retro urinary bladder area and multiple foci in abdominopelvic region, suggesting a peritoneal carcinomatosis. 18F-FDOPA PET was the first imaging modality to assess the extensiveness of the disease that was confirmed six month later by CT. Neuroendocrine tumors are a heterogeneous group of neoplasia. They are studied by conventional radiologic and functional techniques of nuclear medicine. This case illustrates the need to use the different techniques and tracers according to the characteristics of the tumor to be studied to thus improve the diagnostic and prognostic performance.

Aged↗
PubMedDate not supplied

[First diagnostic choice in patients with high clinical suspicion of pulmonary thromboembolism: helical CT or ventilation/perfusion pulmonary scintigraphy?].

AIM: Comparative analysis about helical CT (ThC) vs ventilation-perfusion pulmonary scintigraphy (V/P Sc) diagnosis effectiveness, as a first diagnosis technique in patients with high clinical suspicion of pulmonary thromboembolism (PT). MATERIALS AND METHODS: Prospective study of 30 patients with high clinical suspicion and high Dimer-D levels (> 250 microg/l). The diagnosis was defined as anticoagulant therapeutic prescription and posterior clinical evolution. V/P Sc were performed to each patient within the next 48 h (an average of 14.8 h) after TCh, without anticoagulant treatment. We classified the scintigrams according to the PIOPED criteria and hTC images as positive, negative and indeterminated. RESULTS: In sixteen patients final diagnosis was PT: in 9 both techniques were positive; in 5 scintigraphy was positive with normal hTC and in 1, hTC was normal with negative scintigraphy. The last case was an indeterminated hTC with negative scintigraphy. In fourteen patients, final diagnosis was non-PT: in 6 both techniques were negative; in 7 scintigraphy was negative with positive hTC and in 1, both results were indeterminated. The sensitivity, specificity, positive predictive value, negative predictive value and efficiency were respectively 87.5, 100, 100, 87.5 and 93 % for V/P Sc and 62, 50, 58.8, 53.8 and 53 % for TCh. CONCLUSION: V/P Sc has better PT diagnosis reliability. It is recommended to do V/P Sc in all patients with high clinical suspicion of PT.

Adult↗
PubMedDate not supplied

[Detection of occult malignant melanoma by 18F-FDG PET-CT and gamma probe].

Malignant melanoma has a high relapse rate, and PET is very useful for its detection, above all when its size is small or it is in locations that are difficult to resect. The radioguided surgery being implanted in many sites, new expectations are opening in these situations--the intraoperative location of the lesions by 18F-FDG and detection probe. This is a case report of a 44 years old woman diagnosed of malignant melanoma in her left leg 12 years ago. At present, she has a tumor in her left thigh, which was no longer palpable after a fine needle puncture was performed. This was reported as a mesenchymal tumor. Due to the possibility of recurrent melanoma, need for excision was suggested. In order to locate it, a PET-CT study with 18F-FDG was performed and the lesion was marked on the skin with the help of metallic points. The lesion was located in surgery with a gamma probe, showing relapse of melanoma. The importance of the case is found in the fact that it is the first step to extend the indications of radioguided surgery with the use of PET, a technique that offers a ride range of possibilities.

Adult↗
PubMedDate not supplied

[Clinical utility of fused 67Ga SPECT/CT scan images in patients with lymphoma].

AIM: The aim of this work is to show the clinical utility of the fused SPECT 67Ga/CT images in patients with lymphoma. MATERIAL AND METHOD: 44 patients (22 male) with lymphoma have been studied. 22 with Hodgkin's disease and 22 with non Hodgkin lymphoma. 59 studies were performed (33 thorax-cervical [T], 24 abdomen [A] and 2 skull-cervical area [SC]) with an hybrid gammacamera Millenium VG. We acquire consecutively a whole body scan, a SPECT and a CT, for its fusion with the SPECT, of the affects areas. The images were evaluated by two experts blinded, who classify the contribution of the fusion of images respect to the SPECT like: non changes, it improves the location or changes the extension of the injuries and it changes the staging. Final lesion location was confirmed by a high resolution CT performed within one month. RESULTS: 32/59 studies did not change the location or extension of the injuries (20T, 12A), 23/59 studies changed the location or extension of the injuries (12T, 9A and 2 SC) and on 4/59 the change of location induced a change of staging respect to showed by the SPECT. CONCLUSION: To make fused SPECT 67Ga/CT images in patients with lymphoma allows improving the diagnostic precision in a 46% of the cases, mainly in the abdominal, bone and of the diaphragmatic area studies.

Abdominal Neoplasms↗
PubMedDate not supplied

[Influence of tumor location in patients with breast cancer on the sentinel node detection].

OBJECTIVE: To evaluate the influence of tumour quadrant localization on the sentinel node (SN) detection and the visualisation of internal mammary chain (IM) drainage by radioisotopic techniques. 316 patients with breast cancer were studied. Mean age 57 years (range 29-88). All patients received 37-74 MBq of 99mTc-albumin nanocolloid in 2 ml by peritumoral injection. The breast cancer was located in the upper outer quadrant in 189 patients, in the upper inner in 57, in the lower outer in 57, in the lower inner in 55 and in the subareolar area in 18 patients. At two hours p.i., anterior and lateral chest lymphographies were obtained. The SN location was marked on the patient skin with permanent ink. SN was identified intraoperatively by the gamma probe. Histopatological analysis included imprints, delayed hematoxilin-eosin, inmunohistochemistry CAM 19-2 and PCR. RESULTS: The scintigraphy and surgical detection was in the upper outer quadrant of 90 % and 93 % respectively; in the lower outer quadrant of 91 % and 95 %, in the upper inner quadrant of 93 % and 95 %, in the lower inner quadrant 87 % and 95 % and in the subareolar area in 94 % and 83 %. The IM chain drainage was of 6 % in the UO, in the LO of 5 %, in the UI of 12 %, in the LI of 20 % and none in subareolar. CONCLUSIONS: Our data suggest that sentinel node location (quadrant) is not a influential factor in the scintigraphy and surgical detection. Tumours localised in internal quadrant show a higher rate of IM chain drainage.

Adult↗
PubMedDate not supplied

[Prognostic utility of scintigraphy with 99mTc-HMPAO labelled leukocytes in inflammatory bowel disease].

OBJECTIVE: The inflammatory bowel disease (EII) has a chronic evolution with a frequent relapses. There is no specific diagnosis method to detect the patients with a high risk to relapse. The aim of the work was to analyse the prognostic value of 99mTc-HMPAO leukocyte scintigraphy (LS) performed during an acute attack of EII. MATERIAL AND METHODS: 18 patients (mean age 32 +/- 10 years) admitted for an acute attack of EII has been prospectively studied (5 ulcerative colitis [UC] and 13 Cronh's disease [CD]), excluding patient with prior steroids or immunosuppressive therapy during the last year. LS were obtained in basal conditions and following 3 weeks of steroid treatment and the scintigraphic activity index (SAI) has been calculated. Colonoscopy has been done in all patients, and CDAI in CD and Truelove index in UC have been calculated. Patients were followed up for 1 year. In the evolution the therapy requirements as well as the good response to initial treatment have been evaluated. RESULTS: All patients with UC and 4 patients with CD showed a SAI decrease > 50 % and all had a good clinical evolution. Only 2 out of the 9 patients with CD showing a IAG decrease < 50 % and had a good clinical evolution, the 7 remaining required additional medical treatment (immunosuppressors or surgery). CONCLUSION: LS may be of prognostic value in the management of EII. A SAI decrease > 50 % at 3 weeks of steroid treatment indicates a good clinical evolution.

Adult↗