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Biomedical subjects

R Donzelli

Publications and source records attributed to R Donzelli.

At least 19 recordsLinked to original sources
PubMed2001

Schwannomas of the brachial plexus--diagnostic and surgical problems.

OBJECTIVE: This paper reports four cases of schwannomas of the brachial plexus operated upon with good outcome and discusses the CT and MRI findings and the best surgical treatment of these lesions. DESIGN: All patients had large schwannomas (more than 4 cm in diameter) presenting as painless masses in the supraclavear region, explored by CT and MRI. A homogeneous mass, hypo-isointense in T1- and hyperintense in T2-weighted images, with well-defined margins, is in favor of a schwannoma. The nerve of origin, external to the tumor mass, may be defined on MRI. INTERVENTION: All patients have been operated upon using microsurgical technique: enucleation of the tumor content, piecemal removal of the capsule, identification and preservation of the neural elements were the main goals of the operation in all cases. OUTCOME: Postoperatively, one patient experienced transient deficit of the deltoid muscle (two weeks). Actually, all four patients are symptom-free with no tumor recurrence, 6 months to 7 years after the operation. CONCLUSIONS: A correct preoperative diagnosis of schwannoma of the brachial plexus may be obtained by MRI, which shows a rather typical aspect; on the other hand, needle aspiration histology and open biopsies should be avoided. The microsurgical treatment with preservation of the neural structures, as for schwannomas of the cranial and spinal nerves, results in good outcome without recurrences.

Adolescent↗
PubMed1999

1,4-Dihydropyridine calcium channel blockers inhibit plasma and LDL oxidation and formation of oxidation-specific epitopes in the arterial wall and prolong survival in stroke-prone spontaneously hypertensive rats.

BACKGROUND AND PURPOSE: Calcium-channel blockers (CCBs) reduce systolic blood pressure and stroke-related mortality in stroke-prone spontaneously hypertensive rats (SPSHR). Brain ischemia is associated with loss of intracellular antioxidants. Increased formation of oxygen radicals and oxidation of LDL may enhance arterial vasoconstriction by various mechanisms. CCBs that also exert antioxidative properties in vitro may therefore be particularly useful. To investigate such antioxidant effects in vivo, we determined several parameters of LDL oxidation in SPSHR treated with two 1,4-dihydropyridine-type (1,4-DHP) CCBs of different lipophilic properties and compared them with antioxidant-treated and untreated controls. We also tested whether these drugs decrease the formation of oxidation-specific epitopes in arteries. METHODS: Five groups of 9 to 14 SPSHR each (aged 8 weeks) were treated with 80 mg/kg body wt per day nifedipine, 1 mg or 0.3 mg/kg body wt per day lacidipine, vitamin E (100 IU/d), or carrier for 5 weeks. A group of Wistar-Kyoto rats was used as normotensive control. Plasma samples were taken, and LDL was isolated by ultracentrifugation. Then LDL was exposed to oxygen radicals generated by xanthine/xanthine oxidase reaction (2 mmol/L xanthine+100 mU/mL xanthine oxidase), and several parameters of oxidation were determined. The presence of native apolipoprotein B and oxidation-specific epitopes in the carotid and middle cerebral arteries was determined immunocytochemically. RESULTS: 1,4-DHP CCBs completely prevented mortality. Normotensive Wistar-Kyoto rats showed less oxidation than control SPSHR. Plasma lipoperoxide levels were 0.87+/-0.27 micromol/L in control SPSHR, 0.69+/-0.19 and 0.63+/-0.20 micromol/L in the groups treated with 0.3 and 1 mg lacidipine, respectively, and 0.68+/-0.23 micromol/L in nifedipine-treated animals (P<0.05 versus control SPSHR for all values). Both CCBs significantly decreased formation of conjugated dienes and prolonged the lag time in LDL exposed to oxygen radicals. Similarly, lipoperoxides and malondialdehyde were significantly reduced (P<0.05). Reduced relative electrophoretic mobility and increased trinitrobenzenesulfonic acid reactivity of LDL from treated rats (P<0.01) also indicated that fewer lysine residues of apolipoprotein B were oxidatively modified in the presence of 1,4-DHP CCBs. Finally, these drugs reduced the intimal presence of apolipoprotein B and oxidized LDL (oxidation-specific epitopes) in carotid and middle cerebral arteries. CONCLUSIONS: In the SPSHR model, 1,4-DHP CCBs reduce plasma and LDL oxidation and formation of oxidation-specific epitopes and prolong survival independently of blood pressure modifications. Our results support the concept that the in vivo protective effect of these drugs on cerebral ischemia and stroke may in part result from inhibition of oxidative processes.

Animals↗
PubMed1999

Evidence of exercise-induced myocardial ischemia in patients with primary aldosteronism: the Cross-sectional Primary Aldosteronism and Heart Italian Multicenter Study.

BACKGROUND: Primary aldosteronism (PA) is a disease associated with hypersecretion of aldosterone caused by an aldosterone-producing adrenal adenoma, bilateral adrenal hyperplasia, and, although rarely, by adrenal carcinoma. Arterial hypertension induces several cardiovascular alterations that yield a high cardiovascular risk. It has been shown that reduced myocardial perfusion at rest, assessed by thallium-201 myocardial scintigraphy, was greater in PA than in essential hypertension (EH). However, it is still unknown whether reduced myocardial perfusion at rest and/or regional function abnormalities are present during exercise-induced myocardial stress. PURPOSE: We addressed the impact of PA on myocardial ischemia and sought to identify signs of exercise-induced myocardial ischemia (assessed by MIBI-SPECT and echocardiography) in patients with PA compared to patients with EH. Patients with consistent signs of myocardial ischemia on all of the tests were studied by coronary arteriography. PATIENTS: We studied 72 patients with PA and an age/sex-matched group of 72 patients with EH enrolled in the cross-sectional Primary Aldosteronism and Heart Italian Multicenter Study (PAHIMS). METHODS: Regional function was detected from echocardiographic measurement of wall motion done at baseline and immediately after exercise. Myocardial perfusion was evaluated by SPECT imaging after injecting 99mTc-MIBI with the same-day protocol using the rest-stress sequence. RESULTS: Although the conditions of arterial pressure, duration of hypertension, and target organ damage were equivalent, the patients with PA had greater incidence of both reversible perfusion defects and abnormalities of regional function. Moreover, multiple regression analysis showed that the high plasma aldosterone level was highly predictive for SPECT ischemic score and wall motion index, suggesting that PA contributes to cardiovascular risk over and above that associated with ventricular hypertrophy. Exercise-induced myocardial ischemia in PA was not segmental but widely distributed suggesting that this phenomenon was not related to abnormal coronary perfusion. Accordingly, of the 38 patients with PA who underwent coronarography, there was no presence of significant coronary atherosclerotic lesions in 30 (78.9%) of the patients. CONCLUSIONS: The PAHIMS observed more exercise-induced moderate myocardial ischemic defects (co-detected by SPECT and echocardiograms and not segmental but widely allocated) in patients with PA than in patients with EH. This phenomenon occurred in a greater percentage of patients with PA without significant coronary lesions (78.95%, n = 38), which supports the possible presence of small-vessel intramyocardial disease.

Adult↗
PubMed1998

Anomalous meningeal branches of the ophthalmic artery feeding meningiomas of the brain convexity.

Many anomalies may involve the ophthalmic and middle meningeal arteries, because of the close relationship of their development. The system of the ophthalmic artery may supply the dural convexity by the middle meningeal artery of ophthalmic origin, the anterior branch of the middle meningeal artery or an accessory meningeal artery. The development and the anatomic arrangement of these anomalous vessels are discussed. Three cases of meningiomas of the brain convexity supplied by anomalous meningeal arteries arising from the ophthalmic artery are described. In one case internal carotid angiography showed an anomalous anterior branch of the middle meningeal artery arising from the ophthalmic artery, whereas the maxillary artery provided only the posterior branch of the middle meningeal artery. In two cases the middle meningeal artery system was normal, but the ophthalmic artery provided an accessory meningeal artery supplying the meningioma. Whereas an ophthalmic origin of the middle meningeal artery is rather common, the angiographic finding of an accessory meningeal artery or an anterior branch of the middle meningeal artery arising from the ophthalmic arterial system is exceptional. The preoperative embolization of dural lesions supplied by anomalous meningeal vessels of ophthalmic origin is dangerous because of the risk of embolization into the ophthalmic circle.

Adult↗
PubMed1998

Territories of the perforating (lenticulostriate) branches of the middle cerebral artery.

The territories of the central branches of the middle cerebral artery (MCA) were examined in 21 injected human brains. It was noted that these central arteries supplied: the caudate nucleus (dorsolateral half of the rostral part of its head; the entire caudal part of the head; the body and rostral portion of the tail in some cases), the putamen (dorsolateral part of its rostral portion, the remainder of the putamen, except the most caudal part occasionally), the globus pallidus (the entire lateral segment, except the ventrorostral and, sometimes, the most caudal part), the basal forebrain (lateral parts of the basal nucleus of Meynert and the nucleus of the diagonal band, as well as fiber bundles in this region), the internal capsule (dorsal and ventrocaudal part of the anterior limb, dorsal part of the genu, dorsal and ventrorostral part of the posterior limb), the corona radiata (a narrow strip close to the internal capsule) and the cerebral cortex (the caudal orbitofrontal cortex occasionally). The presented data may have certain neuroradiologic, neurologic and neurosurgical significance.

Adult↗
PubMed1998

The oculomotor nuclear complex in humans. Microanatomy and clinical significance.

This study has been performed to define better the anatomical structure of the oculomotor nuclear complex and its neuronal components. The oculomotor nuclear complex was examined in fixed and serially sectioned midbrains from 12 adult subjects free from neurological diseases. The complex included the somatic portion, (formed by multipolar motor neurons), and the parasympathetic portion, (formed by oval or fusiform preganglionic cells), on each side of the median raphe. The somatic portion consisted of the lateral somatic cell column and the caudal central nucleus. The somatic column measured from 0.2 x 0.1 mm to 3.4 x 1.4 mm (X = 2.4 x 1.2 mm) in transverse section. It was divided into the principal, intrafascicular and extrafascicular parts. The principal part was subdivided into the dorsal, intermediate and ventral portions. Isolated multipolar neurons were also found in the periaqueductal gray matter, the interstitial nucleus of Cajal, the Edinger-Westphal nucleus and the fibre bundles of the oculomotor nerve. These cells most likely represent the displaced motor neurons of the oculomotor nerve. The caudal central nucleus was 0.8 x 0.6 mm in size. The Edinger-Westphal nucleus consisted of the rostral, ventral and dorsal parts; the longest rostrocaudal diameter of this nucleus measured 7.1 mm. The anatomical data of our study are relevant clinically and allow explanation of the neurologic signs following complete or partial lesions of the oculomotor nuclear complex.

Adult↗
PubMed1998

Microsurgical nervous reconstruction using autografts: a two-year follow-up.

BACKGROUND: To analyze factors influencing surgical results after microsurgical reconstruction of injured nerves. METHODS: We report a series of 32 cases of microsurgical nerve reconstruction after traumatizing lesions using nervous autografts. The series comprises 8 reconstructions of radial nerve, 8 of median nerve, 6 of ulnar, and 10 of sciatic nerve. Motor and sensitive deficits have been evaluated preoperatively using a standard grading. RESULTS: A useful sensory recovery has been obtained in radial nerve, as well as in median and ulnar nerve reconstruction. Good results regarding the motor recovery have been obtained in superior limb nerve reconstruction. Sciatic nerve reconstruction showed the worse results. CONCLUSIONS: There is a big discrepance between superior limb vs inferior limb results. A more than 10 cm gap has a negative influence on the progression of regenerating axons, especially in median and ulnar nerves.

Adult↗
PubMed1995

Multicentrical growth of meningiomas: "spatial" or "temporal" phenomenon.

Small nodules of neoplastic cells protruding from the arachnoidal layer surrounding an intracranial meningioma, completely independent from the tumor mass, have been observed in three patients who underwent primary surgery. The high rate of recurrence for meningiomas after a seemingly total excision has been many times reported, and related to histological subtypes, tumor site, and hormonal influence. In the past meningotheliomatous cell aggregates protruding from the inner surface of the dura mater at a distance of 3 cm from the insertion of globoid meningiomas have been described, and the concept of "localized dural multifocality" emphasized. Probably this concept has to be enlarged to consider meningioma as a "neoplastic disease" with different grade of expression. The presence of unidentified macroscopic or microscopic clusters of neoplastic cells, lying around, more or less close to, the line of insertion of lesion, could render any attempt to gain a "radical" excision useless.

Female↗
PubMed1992

[Complications of trans-sphenoidal surgery of the sellar lesions].

Trans-sphenoidal surgery has a very low rate of complications despite a series of apparently negative anatomo-topographical factors. Complications may be either mechanical or functional, transitory or permanent. The most important complications are: hematoma of the focus, sub-arachnoid hemorrhage, empty sella, liquoral fistula, opto-chiasmatic lesions, arterial lesions, lesions of the cavernous sinus, parenchymal damage, nasal and paranasal mechanical lesions, insipid diabetes, hypopituitarism. The overall mortality rate is 0.4-1% and is always associated with predisposing factors, such as previous treatment, voluminous extrasellar growth, concomitant causes of disease; the most frequent causes of death are: hemorrhagic phenomena in the extrasellar portion of large size adenomas; vascular lesions involving the intracavernous carotid artery; and hypothalamic lesions. The frequency of major complications is in the region of 2.3%. Predisposing factors are: volume, consistency, invasiveness, previous treatment, intratumoral necrotic-hemorrhagic phenomena, age. Surgery is only indicated for some of the above complications, including hematoma of the focus, acute postoperative empty sella, rhinoliquorrhea resistent to conservative treatment, excessive filling of the sellar cavity. All the other possible complications are results or functional alterations which must be treated medically, even if a specific therapy only exists for some (such as early hypotonic polyuria). The series of patients reported here refers to the period 1978-1989 and accounts for a total of 259 trans-sphenoidal operations performed in 245 patients. Of the secondary operations, 6 were due to postoperative complications (hematoma of the focus in 2 cases, rhinoliquorrhea in 2 cases; empty sella and hemorrhagic infarction of a large suprasellar site in the 2 remaining cases). There were 2 deaths related to direct mechanical complications (both caused by hemorrhagic infarction of large tumoural residues and the surrounding cerebral parenchyma). Complications which did not require re-operating were observed in 11 further cases: 6 cases of persistent rhinoliquorrhea which required protracted spinal drainage; 2 cases of deterioration of previous visual deficits unrelated to either hematoma of the focus or empty sella but caused by trauma to optic structures, either directly or on a vascular basis; 3 cases of dyplopia due to oculomotory deficiency. In terms of hypophyseal function, the ex-novo onset of postoperative pan-hypopituitarism and insipid diabetes was only observed in one case.(ABSTRACT TRUNCATED AT 400 WORDS)

Causality↗
PubMed1991

Hemodilution and revascularization for early treatment of stroke: an experimental trial.

A new experimental trial to investigate the usefulness of early therapeutic measures in case of acute I.V.D. has been performed, on the basis of a previous already reported experience. A combined treatment consisting of hemodilution and revascularization starting 16 hours after the onset of cerebral ischemia was tested. The study was performed in a population of 20 New Zealand male rabbits in which an acute cerebral ischemia was achieved by means of extracranial ligation of both common carotid artery and of one vertebral artery. The animals were divided into two groups. 1st group: no treatment; 2nd group: revascularization + hemodilution. Better results were observed in treated group considering either CBF rates or histological changes.

Acute Disease↗
PubMed1987

Antithrombotic effect of indobufen in an experimental model of arterio-arterial microanastomosis in the rat.

Using an end-to-side microanastomosis of the left common carotid into the right common carotid of rats, implementing a potentially thrombogenic situation, we have investigated the possible antithrombotic effect of indobufen, a new antiplatelet drug. In eight of 15 untreated rats the anastomosis was totally obstructed by a single thrombus growing from the anastomotic wall. Indobufen treatment prevented thrombus formation completely in 14 of 15 rats (p less than 0.02). In treated animals indobufen also produced a statistically significant reduction of ADP-induced platelet aggregation relative to basal values. Platelet count were not influenced by drug treatment. Our experimental results suggest the potential usefulness of indobufen as an antithrombotic agent.

Anastomosis, Surgical↗