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Biomedical subjects

M Bonetti

Publications and source records attributed to M Bonetti.

At least 37 records · Page 2Linked to original sources

[Lipids in enteral nutrition: does an optimal ratio between omega-6 and omega-3 exist?].

The ratio between PUFA omega-6 and omega-3 is 3:1 in the unweaned, 5:1 in the young man, 5-10:1 in the adult. The PUFA omega-6 prevail over omega-3 because of elongation and desaturation processes. Linoleic acid is the beginning of the omega-6 series, a-linolenic acid of the omega-3 series. Both acids give rise to PUFA which must be introduced with diet because the human race is not able to synthetize. They represent the 2-6% of total daily caloric intake and correspond about to 10 g every day according to LARN 1986-1987. During some diseases (after surgery, trauma, sepsis, etc.) their need increases until 25-50 g every day, so it is necessary a proper enteral nutrition (EN). For this reason the bromatological composition of diets for EN must respect the physiological ratio between omega-6 and omega-3 PUFA. The composition of 37 diets for EN was examined and it was found that 7 (18%) have a proper ratio between the two series of PUFA. Twenty-three (62%) do not signal any ratio, two have 6:1, two 4.5:1, in three the ratio is in favour of omega-3. Then the concentration of linoleic and alfa-linolenic acid was examined and it was found that 24 (64%) diets signal the concentration of linoleic acid, 10 (27%) of both acids, two have no data about and only one diet reports the concentration of alfa-linolenic acid. A more exact formulation of PUFA into the composition of EN diets is suggested because PUFA are now recognized to play an important role in the fields of inflammation and immunity.

English Abstract↗

Three-dimensional MR myelography of traumatic injuries of the brachial plexus.

PURPOSE: To determine the diagnostic accuracy of three-dimensional MR myelography in the evaluation of traumatic injuries of the brachial plexus. METHODS: Twenty patients with clinical and electromyographic evidence of traumatic brachial plexopathy were examined with three-dimensional MR myelography, conventional cervical myelography, and CT myelography 1 to 9 months after trauma. Three-dimensional MR myelography was performed on a 1.5-T MR unit with a constructive interference in steady state (CISS) technique. For each patient, maximum intensity myelographic projections and multiplanar reconstruction reformatted 1-mm axial sections were obtained from the same 3-D data set. Three-dimensional MR myelographic findings were compared with findings at cervical myelography and CT myelography. Surgical findings were available for comparison in 13 patients. RESULTS: Three-dimensional MR myelography enabled detection of meningoceles with avulsed or intact nerve roots, partial or complete radicular avulsions without disruption of the thecal sac, dural sleeve abnormalities, and dural scars. Assuming cervical myelography and CT myelography as the standards of reference, 3-D MR myelography showed 89% sensitivity, 95% specificity, and 92% diagnostic accuracy in the evaluation of nerve root integrity. CONCLUSION: Three-dimensional MR myelography can show the majority of traumatic lesions that involve the proximal portion of the brachial plexus in a single rapid examination. On the basis of our findings, we propose this technique as a screening examination for patients with traumatic brachial plexus palsy.

Adolescent↗

Effect of different dialysis membranes on platelet function. A tool for biocompatibility evaluation.

Intradialytic coagulative and platelet activation, one of the main consequences of blood-membrane contact, was studied in a group of 5 RDT patients with a comparative evaluation of 3 different dialytic membranes: Cuprophan (CU), Polysulfone (PS) and Cellulose Triacetate (CT). Each patient underwent 5 consecutive dialysis sessions with the above mentioned membranes. Intradialytic platelet activation was studied through a morpho-functional evaluation between the mean platelet volume (MPV) and Serotonin (S), beta-Thromboglobulin (beta-TG) and Platelet Factor 4 (PF4) serum levels. These determinations were made before HD (time 0) and after 30', 120', and 240'. We also checked the intradialytic status of thrombogenesis and fibrinolysis determining aPTT, thrombin time, fibrinogen, antithrombin III (AT III), alpha-2 antiplasmin and plasminogen, at the same time intervals. All membranes tested (CU, PS, CT) caused appreciable intradialytic platelet activation, above all after 15' and at the end of dialysis sessions, more marked for CU than PS or CT. In particular MPV showed a decrease throughout the session (-5% at 30' and -9% at 240') while S, beta TG and PF4 peripheral blood levels showed a significant increase at the same intervals with CU membrane. Lastly coagulative and fibrinolytic parameters showed no significant differences among any of the membranes tested.

Adult↗

[Modern imaging of maxillofacial deformities].

Facial malformations make a wide chapter of maxillofacial abnormalities whose treatment needs an accurate clinical-instrumental analysis to quantify malformation entity and to agree on precise lesion classification and subsequent management. Maxillofacial abnormalities are classified as congenital, growth-related and acquired. Congenital deformities include the alterations present at birth, i.e., craniofacial stenosis, oto-mandibular syndrome. Treacher-Collins and Goldenhar syndrome, facial clefts and lip-palate clefts. Growth-related malformations include the deformities appearing during growth and which are called maxillary dysmorphosis, e.g., hemimandibular hyperplasia, prognathism, maxillary hypoplasia, etc. Acquired malformations are those remaining after trauma or cancer surgery and those which are secondary to fibrous dysplasias of the craniofacial complex. May 1990 through May 1993, forty-two patients with different malformations were examined. The malformations secondary to cancer surgery were not included in our series. A radiologic study including conventional skull radiography, teleradiography and panoramic tomography had been performed for preliminary assessment before axial CT studies and 2D and 3D reconstructions. As for our series, in 20 patients coventional radiology was exhaustive to diagnose the disorder and to supply essential elements for treatment planning while axial CT and 3D reconstructions added no further piece of information. Only in the most complex malformations and in all cases of congenital malformations was axial CT needed to assess the type, extent and entity of the malformations allowing both the diagnosis and adequate surgical planning.

Adolescent↗

[Subarachnoid hemorrhage: assessment in the acute phase with angiography, with high-resolution magnetic resonance (angio-MR)].

Previous reports demonstrated that Magnetic Resonance Angiography (MRA) is a reliable means of diagnosing intracerebral aneurysms. However, in these early studies MRA was performed in patients with cerebral aneurysms already proved by intraarterial angiography. Our study was aimed at investigating the clinical feasibility and the diagnostic accuracy of high-resolution MRA in patients with acute subarachnoid hemorrhage. Twenty-five patients (15 women, 10 men) with CT diagnosis of subarachnoid hemorrhage were prospectively examined with high-resolution MRA within 24 hours of bleeding. All patients underwent intraarterial digital subtraction angiography (IA DSA) immediately after MRA examination. MRA studies were performed with a 1.5-T unit. MRA examinations of the cerebral vessels consisted of axial excitation of two 50-mm volume slabs, with 25% overlap, covering the cerebral circulation from the vertebro-basilar junction to the pericallosal artery. Pulse sequence variables were optimized to reduce voxel size (0.62 x 0.62 x 0.78) and to increase spatial resolution (160-mm FOV, 256 x 256 matrix, 0.78-mm slice thickness) while keeping S/N ratio high. The maximum intensity projection (MIP) reconstruction algorithm was used. The examination lasted nearly 20 minutes. Four MRA examinations (16%) were considered inadequate for diagnosis because of motion artifacts. High-resolution MRA detected 20 of 21 aneurysms in 17 patients, with 1 false positive and 1 false negative. Two patients had multiple aneurysms, 2 and 4 respectively, all of them detected by MRA. No cause of subarachnoid hemorrhage was found by IA DSA in 4 patients, while MRA studies were considered negative in 3 patients. Nineteen aneurysms were surgically clipped, while 2 basilar artery aneurysms were occluded by intravascular treatment. MRA and DSA findings were compared with surgical findings. Relative to IA DSA, MRA exhibited 95% sensitivity and 95% specificity. Aneurysm size ranged 2-10 mm: the smallest aneurysm detected by MRA was 2.5 mm. Anatomical and morphological agreement between MRA and IA DSA was excellent, with only slight MRA underestimation of the aneurysm size in 25% of cases and overestimation in 15% of cases. The aneurysm neck was shown by MRA in 60% and by IA DSA in 81% of cases. High-resolution MRA proved to be especially useful in complex anatomical sites where the direction of the aneurysm could be clearly demonstrated through the accurate selection of the appropriate projection angle and the careful examination of direct axial images.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗

Hepatic tumor and tumor-like lesions in childhood.

Tumors of the liver are rare in infancy and childhood. Some are peculiar to the pediatric age, e.g., hepatoblastoma, infantile hemangioendothelioma, mesenchymal hamartoma, embryonal rhabdomyosarcoma. This review is based upon personal experience with a series of 32 cases. On the basis of the histological features it is proposed that focal modular hyperplasia (FNH) and mesenchymal hamartoma be considered as tumor-like lesions rather than true neoplasms. A few benign epithelial lesions (FNH, adenoma) were associated with inborn error of metabolism. In half of the patients, hepatocellular carcinoma (HCC) developed in perinatally hepatitis B virus (HBV)-infected children. HCC developed in a noncirrhotic liver in a single patient, in whom HBV-DNA integration had occurred.

Carcinoma, Hepatocellular↗

Oral anticoagulant therapy control: evidence that INR expression improves the inter-laboratory comparability of results--the Bologna oral anticoagulant control exercise.

The aims of the present study were: 1) interlaboratory normalization of prothrombin time (PT) testing for anticoagulant therapy control through calibration of customary thromboplastins against international reference materials, and 2) "on field" validation of the advantages offered by expression of results as International Normalized Ratio (INR) as opposed to percentage activity. PT tests were carried out over 8 days on the same normal subjects (16) and patients on oral anticoagulants (48) in the 9 laboratories of the Bologna area. The use of customary thromboplastins and coagulometers was maintained in all labs throughout the study. The main results were: 1) the interlaboratory CV of the prothrombin ratios obtained for each sample with all customary thromboplastins (5 different brands) was 15%, but was reduced to levels of 5.8 to 8.9 when using constant thromboplastin brands and batches; 2) the International Sensitivity Index (ISI) values obtained in the different labs were only slightly influenced by the use of different coagulometers; 3) comparable ISI values were obtained through direct calibration with the international reference material and through intermediate calibration with a locally selected standard; 4) use of INR values instead of percentage activity greatly reduced interlaboratory variability and significantly improved uniformity of anticoagulation level measurements, thus reducing the possibility of erroneous prescriptions. The Bologna exercise is therefore of educational value for laboratory and community doctors of the area in understanding and accepting the INR system.

Administration, Oral↗

A simple method of predicting left ventricular function in stabilized chronic respiratory failure.

A simple method of assessing left ventricular function in stabilized chronic respiratory failure (CRF) is proposed. 21 patients with CRF were ranked according to the prediction of left ventricular function derived from eight elementary clinical criteria including standard chest X-ray and conventional basal electrocardiography. Equilibrium radionuclide angiocardiography was performed at rest (rERNA) for the evaluation of left ventricular systolic function (ejection fraction, LVEF; peak ejection rate) and diastolic function (peak filling rate). Right ventricular ejection fraction (RVEF) was also measured. The clinical evaluation of the left ventricular function showed a high correlation with rERNA data (p less than 0.01 by Spearman's rank test). No correlation was found between rERNA parameters and PaO2 and between RVEF and LVEF. The clinical criteria proposed can thus predict left ventricular function in stabilized CRF with a high degree of confidence.

Angiocardiography↗

[Role of cerebral magnetic resonance angiography in childhood].

This study evaluates the role of cerebral MR Angiography (MRA), as a part of the flowchart for the assessment of the brain in childhood. This noninvasive technique provides intra- and extra-cranial anatomic and physiologic vascular information, with a level of precision almost equal to that of arterial angiography. Indeed, MRA has reached a level of diagnostic accuracy such that the need for arterial angiography can be avoided, in most cases of cerebrovascular disorder. Therefore arterial angiography could be performed at the subacute (and more neurologically stable) stage, or presurgically, yielding additional morphologic and hemodynamic insights into cerebrovascular disease. MRA is also indicated at follow-up examination, and in treatment planning.

Brain↗