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Biomedical subjects

F Bui

Publications and source records attributed to F Bui.

At least 37 records · Page 2Linked to original sources
PubMed1998

Ultrasonography of the Abdominal Aorta: The Right Flank vs the EPI-Mesogastric Windows.

Ultrasonography of the abdominal aorta should be performed as part of a complete echocardiographic study. As visualization may be difficult from the epi-mesogastric (E-M) window because of obesity or distension, we evaluated the feasibility of the right flank (RF) as an alternative acoustic window in 100 patients (62 male, 38 female, aged 7-83 years). Compared with the E-M window, our results showed that the right flank was significantly better in imaging of the infrarenal aorta: 89% (RF) vs 75% (E-M) (p < 0.05); right renal artery: 84% vs 71% (p < 0.05); and right renal artery Color Doppler: 84% vs 71% (p < 0.05). The Doppler sonification angle for the right proximal renal artery was 0 degrees-31 degrees (mean 12.7 degrees +/- 4.2 degrees) vs 64 degrees-76 degrees (mean 70.6 degrees +/- 4.1 degrees); for the left proximal renal artery 0 degrees-35 degrees (mean 23.1 degrees +/- 6.6 degrees) vs 62 degrees-73 degrees (mean 68.3 degrees +/- 4.2 degrees). Images obtained from the right flank were often of better quality than those obtained from the abdominal window because of a superior definition of acoustic interfaces and a better performance of Color Doppler sampling. Thus, the right flank could be considered a good alternative window for the echographic study of the abdominal aorta.

Journal Article↗
PubMed1998

99mTc-HMPAO SPECT in the diagnosis of brain death.

OBJECTIVE: To evaluate the effectiveness of single proton emission tomography (SPECT) with 99mTc-HMPAO in the diagnosis of brain death (BD). DESIGN: Prospective study in comatose and brain-dead patients. SETTING: Neurologic ICU. PATIENTS AND METHODS: Fifty comatose patients (age range: 10 days-75 years) were submitted to SPECT study. In 21 of them (42%) reversible factors (e.g., influence of drugs affecting the central nervous system) were present. Thirty-eight patients were clinically brain-dead, while the remaining 12 were tested both in pre-terminal conditions and after the clinical onset of BD. INTERVENTIONS: Brain SPECT following i.v. injection of 99mTc-HMPAO (300-1100 MBq), using a 4-headed gamma-camera (20 min, 360 degrees, 88 images). MEASUREMENTS AND RESULTS: All patients tested in pre-terminal conditions showed preserved brain perfusion. Two of them had flat EEGs despite the absence of any reversible cause of coma; three patients survived, but remained in persistent vegetative states. SPECT confirmed the diagnosis of BD in 45 out of 47 patients (95.7%), clearly showing the arrest of brain perfusion (picture of "empty skull"); in two clinically brain-dead children (aged 10 days and 12 months, respectively) weak perfusion of the basal ganglia, thalamus and/or brain stem was still present, precluding the diagnosis of BD; both of them died a few days later. CONCLUSIONS: Our results confirm the reliability of SPECT in the diagnosis of BD. A problem arises about its effectiveness in brain-dead children, but this seems to be a matter of definition of BD and cerebral viability, rather than a limit of SPECT.

Adolescent↗
PubMed1998

Assessment of brain perfusion in coma and comparison between SPECT and CT scan data: preliminary report.

In this study we submitted 24 comatose patients (Glasgow Coma Score <8) to Single Photon Emission Tomography (SPECT) during the clinical course of coma to verify its utility and the relationship between SPECT and CT scan data. SPECT was recorded following i.v. injection of Xe-133 in 17 patients and of Tc-99m-HMPAO or Tc-99m-ECD in the remaining 7. SPECT data recorded during the acute phase of coma did not show a clear correlation between cerebral blood flow (CBF) and outcome. SPECT and CT scan detected abnormalities in the same areas in 6 cases (25%); 6 patients (25%) with focal CT-scan lesions showed no focal CBF alterations in the same regions; conversely, in the remaining 12 cases (50%) SPECT disclosed severe perfusion abnormalities where no lesions were detectable on CT-scan. SPECT allowed us to recognize different regional flow patterns, such as absolute or relative hyperemia or oligoemia, which could not be checked with other means, thus improving patient's management. Apart from cerebral ischemia, there was no relationship between lesions on CT-scan and flow pattern. Our preliminary results suggest that SPECT can improve both the knowledge of patient's neurological conditions and management in comparison to the use of only CT scan.

Adolescent↗
PubMed1998

[99mTc pertechnetate scintigraphy and premedication for the search for ectopic gastric mucosa in Meckel's diverticulum].

BACKGROUND: Meckel's diverticulum (MD) is the most common anomaly of the large intestinal tract (1-3%) and is more frequent in children (62% < 2 years) and in males (66%). It often involves ectopic gastric mucosa which manifests through gastrointestinal bleeding in 50% of cases. 99m-Technetium scintigraphy (99mTcO4) is one of the procedures available for the non-invasive diagnosis of ectopic gastric mucosa. METHODS: Twenty-eight patients (11 females, 17 males), including 16 children and 12 adults, aged 8 months-80 years old, were included in the study. The patients were admitted to hospital for hematochezia and melena (22) associated with abdominal pain (5): 3 patients repeatedly presented occult blood in their stools. Two patients only suffered from abdominal cramps and one only anemia. Patients were studied using plain abdominal radiographs and ultrasound; 10 underwent gastroscopy and colonoscopy; radiological contrast studies were performed in 5 patients. All tests were inconclusive. All the patients were premedicated with oral cimetidine (20 mg/kg in pediatric patients and 300 mg q.i.d. for adults, 48 hours before the test) or with ranitidine i.v. (1 mg/kg, max 50 mg, in 20 minutes, one hour before the test); barium meals and colonoscopy were deferred for 2-3 days after examination. An intravenous injection of 37-180 Mbq of 99mTcO4 was given followed by a dynamic study of the abdomen in anterior projection. Images were acquired for one hour or until the visualisation of abnormal foci of intake: in this case, lateral and oblique images were acquired for a better localisation of the suspicious area. Some patients were administered furosemide i.v. (0.75 mg/kg). All underwent a follow-up period of 12 months. RESULTS: Pertechnetate scintigraphy was positive in 10 cases and the presence of ectopic gastric mucosa was confirmed by surgery. The study was negative in 18 cases: 3 of them were discharged with a diagnosis of Salmonella infection, polyp of the small bowel or ulcer of the large bowel respectively; the other 15 patients did not show symptoms of onset during follow-up. CONCLUSIONS: These results confirm the high diagnostic accuracy of pertechnetate scintigraphy to detect ectopic gastric mucosa if associated with H2-receptor-blocking agent premedication.

Adolescent↗
PubMed1995

The McGill Quality of Life Questionnaire: a measure of quality of life appropriate for people with advanced disease. A preliminary study of validity and acceptability.

This is the first report on the McGill Quality of Life Questionnaire (MQOL), a questionnaire relevant to all phases of the disease trajectory for people with a life-threatening illness. This questionnaire differs from most others in three ways: the existential domain is measured; the physical domain is important but not predominant; positive contributions to quality of life are measured. This study was conducted in a palliative care setting. Principal components analysis suggests four subscales: physical symptoms, psychological symptoms, outlook on life, and meaningful existence. Construct validity of the subscales is demonstrated through the pattern of correlations with the items from the Spitzer Quality of Life Index. The importance of measuring the existential domain is highlighted by the finding that, of all the MQOL subscales and Spitzer items, only the meaningful existence subscale correlated significantly with a single item scale rating overall quality of life.

Adult↗
PubMed1995

[Nuclear medicine methods for the diagnosis of adrenal tumors].

Adrenal scintigraphy using 131I-6-beta-iodomethyl-19-norcholesterol or 6-methyl-75Se-methyl-19-norcholesterol is a function-dependent imaging method which, in association with high-resolution spatial imaging techniques, plays an essential role in the study of adrenocortical hyperfunction. It can distinguish between bilateral cortical hyperplasia and monolateral adenoma or carcinoma and can lateralise the adenoma. In patients with Cushing syndrome, in addition to allowing a distinction to be made between ACTH-dependent forms and independent forms, adrenocortical scintigraphy is particularly appropriate to identify non-common forms of adenomatous hyperplasia. Adrenocortical scintigraphy, performed during dexamethasone administration, is an accurate mean of differentiating bilateral adrenal hyperplasia from monolateral forms (adenoma or carcinoma) in patients with Conn's syndrome. Owing to the gradual spread of high-resolution spatial imaging techniques, the problem of the diagnostic classification of so-called "incidentalomas" (clinically silent masses discovered by chance) is a subject of considerable interest. Adreno-cortical scintigraphy appears to be able to provide an important contribution to identifying the functional behaviour of these tumours. Since the early 80s meta-iodobenzyl-guanidine (MIBG), marked with 131I or 123I, with a structure similar to norepinephrine and characterized by selective tropism for sympathetic and chromaffin tissue, has been used for the scintigraphic study of adrenal medulla. MIBG scintigraphy has been found to be particularly appropriate for the study of intra- and extra-adrenal, single and multiple, benign and malignant pheochromocytomas. This method has a high overall sensitivity and specificity. Lastly, MIBG scintigraphy is useful in the study of neuroblastoma.

3-Iodobenzylguanidine↗
PubMed1995

Whole body and tomographic scan with 111In-pentetreotide: preliminary data.

Since December 1993, in the 1st Nuclear Medicine Service of the University of Padua, eleven somatostatin-receptor scintigraphic studies with 111In-labelled pentetreotide have been performed. The patients (6 men and 5 women, age 28-68, mean 45 years) were affected by a variety of tumors which supposedly express somatostatin receptors: 2 meningotheliomatous meningiomas post-surgery; 2 glucagonomas with liver metastases observed on CT; 2 patients with suspicion of insulinoma; 2 carcinoids, one after surgery; 1 ectopic-ACTH Cushing's syndrome; 1 intracranial germinoma, post-surgery, in whom the study was requested to evaluate a doubtful finding of pulmonary metastatic lesion on CT; and 1 acromegaly showing, on MRI, and empty sella turcica occupied by and extraflexion of the lower portion of the chiasmatic cisterna without signs of adenoma and the sphenoidal sinus occupied by tissue wit inflammmatory characteristics. Somatostatin-receptor whole body scintigraphy was performed 4 and 24 hours after intravenous injection of 110 MBq 111In-pentetreotide (Octreoscan 111); spot images were acquired when judged necessary. In one case of glucagonoma, a tomographic scan (SPECT) was also performed to better evaluate the spatial relationship between the primitive pancreatic tumor and surrounding tissues. Focal accumulation of 111In-pentetreotide was scintigraphically detected in 5 of the 11 cases. Intense uptake of the radiopharmaceutical was observed in the meningiomas, in the glucagonomas with liver metastases, and in the case of acromegaly, corresponding to a GH-secreting adenoma. The negative scans seem to be true negative scans with the possible exception of one patient with a still unconfirmed suspicion of insulinoma, still not confirmed.

ACTH Syndrome, Ectopic↗
PubMed1993

Acromegalic cardiopathy: a left ventricular scintigraphic study.

In order to study "acromegalic cardiomyopathy", cardiac function was examined, using gated radionuclide ventriculography, in 18 acromegalic patients and 21 control subjects with no clinical evidence of cardiac involvement. In these acromegalic subjects, while the Ejection Fraction (EF) did not appear to be significantly different, the Peak Filling Rate (PFR) was reduced while the Time to Peak Filling Rate (TPFR) resulted significantly greater than in control subjects. These findings indicate that chronic growth hormone (GH) hypersecretion, as observed in acromegaly, deteriorate the cardiac ventricular relaxation (diastolic phase) while it has no influence on contractility (systolic phase).

Acromegaly↗
PubMed1991

Comparison of the antihypertensive and renal effects of tertatolol and nadolol in hypertensive patients with mild renal impairment.

The antihypertensive and renal haemodynamic effects of 5 mg/day tertatolol (T), a new nonselective and long-acting beta-adrenoceptor blocker, and 80 mg/day nadolol (N) in hypertensive patients with mild renal impairment have been compared in a randomized double-blind trial. Before and after 30 days of active treatment glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were determined by use of a simultaneous i.v. bolus of 99mTc-DTPA and 131I-hippuran. Both T and N significantly decreased blood pressure and heart rate, and induced an insignificant increase in GFR and ERPF. There were no differences between the effect of the treatments on blood pressure and heart rate. Despite the persistent fall in BP and HR, renal function was maintained during both T or N treatment, suggesting that both drugs may act by a direct intrarenal vasodilator mechanism.

Adrenergic beta-Antagonists↗
PubMed1990

[Evaluation of decontamination procedures used at digestive endoscopy units in Gironde].

Decontamination procedures used for endoscopes were noted in 23 digestive endoscopy units, public and private, in the department of Gironde and compared to recommended procedures. Serial, bacteriological samples were obtained from one esogastroscope and one colonoscope in each unit, after upper endoscopy and colonoscopy diagnostic procedures at the end of the endoscopy session. Six units of 23 used complete decontamination procedures. In the 17 other units, principal errors of decontamination procedures were: inadequate cleaning of internal channel of scopes (12 units) and lack of utilization of glutaraldehyde between each endoscopy (8 units). Bacteriological samples were negative in 11/12 endoscopes after a complete decontamination procedure and in 8/39 after an inadequate procedure (p less than 0.01). Complete procedures are efficacious but not used often enough. Information and changes in endoscopic practices are necessary in digestive endoscopy units.

Bacterial Infections↗
PubMed1988

Radionuclide evaluation of lung perfusion after the Fontan procedure.

Lung perfusion was evaluated in 19 patients in whom a Fontan operation had been performed at a mean age of 3.7 years. First pass and equilibrium data were acquired during the lung particle perfusion scan 0.5 to 7.9 years (mean 3.7 years) following the Fontan procedure. Abnormalities of lung perfusion were documented in 8 patients. Minimal underperfusion of small areas of either right or left lung were noted in 4 patients, while the remaining 4 had evidence of major perfusion defects, involving both lungs. The perfusion defects were localized, in the majority of cases, on the side where a palliative procedure had been performed before the Fontan operation: it is of note that all our patients without palliative procedures did not show abnormalities in lung perfusion. Major abnormalities of lung perfusion seemed related to possible intimal thrombosis or emboli due to prolonged polycythemia or to pulmonary vessel distortion due to long-standing shunts.

Child↗
PubMed1988

Short-term and stabilized effects of percutaneous nephrolithotomy on the kidney.

A homogeneous group of 15 patients was investigated before and after percutaneous nephrolithotomy (PCN). Creatinine and electrolyte clearances evaluated both before and during saline (NaCl 0.9%) infusion, 4-7 days after PCN remained unchanged with respect to the preoperative values. A significant decrease of urinary PGE2 was observed postoperatively both before and after extracellular volume expansion. 99mTc-DTPA renography performed 26-40 days after surgery showed a scar on the convex margin of one kidney in the area of the nephrostomy and an improved renographic curve in 5 renal units. No difference between pre- and post-PCN isotopic clearances was evident. On the basis of our results we can affirm that PCN is an efficient and safe method for the treatment of nephrolithiasis.

Adult↗
PubMed1985

Adrenal scintigraphy in the morphological and functional evaluation of Cushing's syndrome.

In recent years, cholesterol adrenal scintigraphy has been employed in the morphofunctional study of adrenal hypercorticism. Particularly in Cushing's syndrome, this noninvasive procedure can give a determinant contribution to distinguish ACTH-dependent from ACTH-independent forms. In our Institute, adrenal scintigraphy was performed in 77 patients with Cushing's syndrome diagnosed on clinical grounds confirmed by laboratory investigations and functional tests (17 with cortisol-secreting adenoma, 54 with pituitary ACTH-dependent bilateral adrenal hyperplasia, 2 with ectopic ACTH-dependent bilateral hyperplasia and 4 with bilateral nodular hyperplasia). Three distinct scintigraphic patterns have been identified. The 56 patients with ACTH-dependent Cushing's syndrome showed bilateral symmetric or slightly asymmetric visualization of the adrenal glands; in the 17 patients with ACTH-independent Cushing's syndrome the adrenal scintigraphy only visualized the gland harboring the adenoma; finally, a marked asymmetric visualization of the glands was observed in the 4 patients with adrenal nodular hyperplasia. These data confirm that adrenal scintigraphy is able to distinguish between ACTH-dependent and ACTH-independent Cushing's syndrome and reliably lateralizes adenomas when they are present. Moreover, the morphofunctional information obtained by this procedure, together with the high resolution morphological data by computerized tomography, allows to recognize the presence of bilateral nodular hyperplasia, an uncommon cause of Cushing's syndrome.

ACTH Syndrome, Ectopic↗
PubMed1985

Role of the diuresis renogram in the study of the pelviureteric junction.

A consecutive series of 29 patients (33 pelviureteric units) with urographic signs of altered passage through the pelviureteric junction underwent diuresis renography performed by means of an intravenous injection of 99mTc-diethylenetriamine pentaacetic acid/kg body weight followed by intravenous administration of frusemide. Anderson-Hynes pyeloplasty was performed in 19 pelviureteric units with a modest or almost absent fall in the renographic curve after diuretic injection; 2 other symptomatic patients, in whom a moderate fall of the same curve was found also underwent surgery. Complete normalization of the renogram was observed in 17 of 21 operated patients. Severe functional deficit and polymegacalicosis were evident in 3 and 1 patient, respectively, with unchanged postoperative renograms. During follow-up (6 months to 2 years) diuresis renography remained unaltered in non-operated units. Our experience indicates how the diuresis renogram not only gives functional confirmation of a pelviureteric junction obstruction, but is also helpful in resolving situations in which there is a discrepancy between symptoms and urographic signs. Furthermore it provides an accurate method for evaluating the results of pyeloplasty. However, the use of this investigation is not, in our opinion, indicated in the presence of severe functional deficit of the kidney or pyelectasis.

Adolescent↗
PubMed1983

Different rates of thyrotropin suppression after total body scan in patients with thyroid cancer: effect of an optimal saturation regimen with thyroxine or triiodothyronine.

The rate of TSH suppression in patients with differentiated thyroid cancer, when therapy is re-started after total body scan, was investigated adopting an optimal saturation regimen, either with T4 or with T3. The first group of 6 patients received T4 as follows: from day 1 to 7 = 22, 11, 6, 4, 3.5, 3.2, 3.2 micrograms/day/kg body weight (b w) and continued with 3.2; the second group of 8 patients received T3 as follows: 2.4, 1.8, 1.4, 1.2, 1.1, 1.1 micrograms/day/kg BW and continued with 1.1. At time 0, TSH levels were high in all patients (range 80-180 microU/ml); T3 and T4 levels were below the limit of detectability. After the beginning of the therapy, the decrease of TSH levels and the inhibition of TSH response to TRH occurred faster in patients taking T3 than in patients taking T4. In the former, at day 7, mean basal TSH level was 1.9 +/- 0.5 microU/ml and 30 min after 200 micrograms TRH iv mean TSH level was 9.9 +/- 4.4 microU/ml; at day 10 they were 1.4 +/- 0.5 and 2.7 +/- 0.8 microU/ml respectively. In the latter, at day 7, mean basal TSH level was 4.6 +/- 3.9 microU/ml and 30 min after TRH mean TSH level was 42.2 +/- 34.2 microU/ml. Only at day 20 they were 0.8 +/- 0.2 and 1.2 +/- 0.9 microU/ml respectively. In patients taking T3 by saturation regimen, serum levels of T3 rose rapidly to supranormal values (at day 3, mean serum T3 level was 297 +/- 62 ng/100 ml), reached a peak at day 5 (340 +/- 62 ng/100 ml) and decreased thereafter, always remaining however above normal limits.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1980

Sequential deiodination of thyroxine to 3,3'-diiodothyronine via 3,5,3'-triiodothyronine and 3,3',5'-triiodothyronine in rat liver homogenate. The effects of fasting versus glucose feeding.

The characteristics of thyroxine (T4) deiodination to 3,5,3'-triiodothyronine (T3) and 3,3',5'-triiodothyronine (rT3) and of each of the latter to 3,3'-diiodothyronine (3,3'T2) were examined in rat liver homogenate. Each of the four reactions was enzymatic in nature, demonstrating pH and temperature optima, and tissue and time dependence. All reactions were considerably augmented (greater than 10-fold) by the presence of a thiol agent. At pH 7.2 with 2 muM T4 as substrate, rT3 generation was 3.3 +/- 0.44 (S.E.) and T3 formation was 4.8 +/- 0.57 pmol/min/100 mg of homogenate protein. Fasting for 72 h resulted in a significant inhibition of T4 deiodination, compared to that in the glucose-fed animals, in a 2% homogenate preparation. Enzyme activity for T4 to T3 was reduced by 54% (p less than 0.05) in the homogenate from the fasted rats. Fasting lowered the enzyme activity of T4 to rT3 by 56% (p less than 0.05). Although the monodeiodination of T3 to 3,3'-T2 was also significantly depressed (p less than 0.01) by fasting, rT3 deiodination to 3,3'-T2 was not. The in vitro additon of 5 mM dithioerythritol did not reverse the effect of fasting on any reaction. These results demonstrate that a 72-h fast significantly impairs the sequential deiodination of T4 in liver homogenate. The effect of fasting appears to be mediated mainly through a reduction in enzyme concentration rather than co-factor availability.

Animals↗