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Biomedical subjects

N Graziani

Publications and source records attributed to N Graziani.

At least 19 recordsLinked to original sources

Multiple roles for the yeast SUB2/yUAP56 gene in splicing.

The UAP56 gene has been shown to be required for prespliceosome assembly in mammals. We report here the isolation of the Schizosaccharomyces pombe ortholog of this gene by heterologous complementation of a combined PRP40HA(3)/nam8Delta defect in budding yeast. The Saccharomyces cerevisiae ortholog, YDL084w/SUB2, is also able to suppress this defect. We show that SUB2 is involved in splicing in vivo as well as in vitro. Sub2 defective extracts form a stalled intermediate that contains U2snRNP and can be chased into functional spliceosomes. Our experiments also suggest a role for this protein in events that precede prespliceosome formation. Data reported here as well as in the accompanying papers strongly implicate Sub2p in multiple steps of the spliceosome assembly process.

Amino Acid Sequence↗

Centrifugal pumps and heparin-coated circuits in surgical treatment of giant cerebral aneurysms.

Giant cerebral aneurysms may be untreatable by conventional neurosurgical techniques. Early attempts to use circulatory assistance and deep hypothermia were abandoned due to hemorrhagic complications. More recently, interest in circulatory support for complex neurosurgical procedures has been renewed. A consecutive series of 8 patients were operated on for giant cerebral aneurysms with the combined use of deep hypothermia. The protocol included careful preoperative cardiovascular assessment, perfect intraoperative synergy between neurosurgical and cardiac teams, minimally invasive peripheral vascular access including two femoral vein (21 F) and single arterial (17 F) femoral cannulation, use of total Carmeda coating on BioMedicus pumps in closed circuits, and reduced heparinization without Protamine reversal. All cerebral aneurysms were successfully treated through deep hypothermia (15-18 degrees C) as assessed by intraoperative fluoroscopic controls and Doppler vascular assessment. Mean circulatory support time was 174.2 +/- 29.6 min. Circulatory arrest period was 20 +/- 12 min. All patients survived and were extubated within 48 h. No major deficit was observed clinically or on postoperative CT scan. No hemorrhagic complications occurred (mean transfusions was 2.2 blood units). This work supports an extensive use of heparin-coated surfaces for complex circulatory assist techniques, either for cardiac or extra cardiac complex procedures.

Adolescent↗

Anterior lumbosacral dislocation: case report and review of the literature.

BACKGROUND: Anterior lumbosacral dislocation is a rare traumatic anterior spondylolisthesis. METHODS: We report a new case surgically treated and review the eight cases previously reported. RESULTS: The mechanism of injury is hyperflexion-distraction. Neurological signs are inconsistent. Indirect radiological signs such as bilateral multiple transverse process fractures are strongly suggestive of the diagnosis. This complete soft tissue injury induces a definitive instability and requires an open reduction with posterior fixation. CONCLUSIONS: Suspicion of lumbosacral dislocation requires a computed tomography scan exploration with multiplanar reconstructions. Early reduction is associated with neurologic recovery. However, prognosis is correlated with the initial neurologic status and the severity of other associated injuries.

Adult↗

The contribution of cytogenetics to the histogenesis of meningeal hemangiopericytoma.

Some controversy has existed regarding the nosology of meningeal hemangiopericytoma. In the WHO's classification of 1979 these tumours were included as a subgroup of meningiomas, but for some authors, they should not be classified as meningiomas. Cytogenetic studies on meningioma demonstrate monosomy or partial deletion of chromosome 22 in 60% of these tumors. There have been few cytogenetic studies about meningeal hemangiopericytoma. We present here the results of cytogenetic studies and fluorescence in situ hybridization in six cases of meningeal hemangiopericytoma. In these tumours we have never found monosomy 22, but all six cases were hyperdiploid. These cytogenetic data might provide additional evidence to differenciate the meningeal hemangiopericytoma from the meningioma.

Adolescent↗

[Angiographically occult vascular malformations of the brain stem. Apropos of 25 cases].

Due to the current use of magnetic resonance imaging (MRI), angiographic occult vascular malformations (AOVM) located in the brain stem are frequently reported in the last ten years. The term AOVM is ambiguous and controvers. For, most of these lesions presented with MRI pattern of a cavernous angioma, but only few cases received pathological confirmation. In this location, the operative treatment while worthwhile could be hazardous indeed, so a conservative management is more commonly discussed first. However, the potential risk of rebleeding or poor clinical condition sometimes encourage a more aggressive decision. We report our experience in 25 patients (4 children and 21 adults) admitted between 1982 and 1994 with an AOVM located in the brain stem. In 17 patients, the cryptic vascular lesion was removed surgically. A cavernous angioma was strictly confirmed in only 8 cases. Conversely, 8 patients were managed conservatively. In the surgically treated group of patients, 10 improved their neurological deficit postoperatively, 2 patients remained unchanged, 3 patients worsened, and 2 patients died. The final outcome in 14 patients was evaluated after 51 months of mean follow-up (17 to 70 months). In 5 cases (35.7%) the result was excellent (no symptoms), 5 cases had a good result (normal activity with minimal residual disability), and 4 cases (28.5%) remained with severe permanent disability. In the non-surgically treated group of patients, the final outcome was evaluated after a mean follow-up period of 67 months (from 1 to 120 months). One patient experienced a rebleeding and remained severely disabled. Another patient had two bleeding episodes leaving only a minor facial numbness. Four patients were symptom-free, and the last case was lost for follow-up.

Adolescent↗

Do the suprasellar neurenteric cyst, the Rathke cleft cyst and the colloid cyst constitute a same entity?

Two cases of entirely suprasellar cysts are reported. Total surgical removal was performed in both cases. Pathological and immunohistochemical profiles were consistent with neurenteric cysts, Rathke's cleft cysts or colloid cysts and was also in keeping with an endodermal origin. It is now admitted that these three kinds of cysts share similar histological and immunohistological features. We propose an hypothesis of common embryological origin from endodermal remnants.

Adult↗

A comparison of extradural and intraparenchymatous intracranial pressures in head injured patients.

The reliability of extradural pressure measurements for the measure of intracranial pressure (ICP) is still controversial. This study was undertaken to assess the limits of agreement between extradural and intraparenchymatous pressures using respectively the Plastimed extradural sensor and the Camino fiberoptic system. The study took place in a neurosurgical intensive care unit. Ten head injured patients were included in the study, leading to the comparison of 1032 pairs of hourly ICP values. Although the measures were significantly correlated, there was no agreement between the two methods of ICP monitoring. Extradural pressure was higher than intraparenchymatous pressure (bias 9 mmHg; 95% confidence interval of bias -9.8 to 27.8 mmHg). The lack of agreement between the two methods is probably due to the unreliability of extradural pressure for the measurement of ICP.

Adolescent↗

[Meningoradiculitis and bilharziasis].

A 55-year-old French man was admitted with acute retention of urine. Three days before admission he developed back pain, lower limb pain and weakness. He had last been in Nigeria 2 years previously. Schistosoma mansoni ova were identified on rectal mucosal biopsy. Our patient showed spontaneous clinical improvement. He was treated with Praziquantel and corticosteroids. The clinical manifestations of spinal schistosomiasis can be diverse, and there should be a high index of suspicion for all patients from endemic areas. Currently, praziquantel and corticosteroids are the drug of choice for Schistosoma mansoni infection.

Humans↗

Glycosylated and non-glycosylated prolactin forms are increased after opioid administration as part of surgical anaesthesia.

OBJECTIVE: Previous studies have shown that non-glycosylated prolactin (NG-PRL) increased more markedly than glycosylated hormone (G-PRL) after TRH or metoclopramide stimulation. The aim of the present study was to determine whether such results could be extended to opioid-induced PRL stimulation. DESIGN: Open and prospective study. Using a newly developed IRMA specific for NG-PRL, we determined G-PRL and NG-PRL immunoreactivities after administration of 0.8-1.2 mg of the opioid drug phenoperidine as part of an anaesthesia. PATIENTS: Ten male patients anaesthetized for surgical treatment of a prolapsed lumbar intervertebral disc. MEASUREMENTS: Samples were obtained hourly pre and post-operatively, and every 15 minutes during operation for determination of plasma PRL, NG-PRL and G-PRL. Plasma cortisol, ACTH and GH levels were measured in an attempt to differentiate the respective roles of stress and opiate agonists in the variations of PRL levels during surgery. RESULTS: A dramatic increase in PRL levels was observed in all patients from an average of 300 +/- 90 to 1200 +/- 330 mU/l (mean + SEM) 30 minutes after drug administration. The proportion of G-PRL immunoreactivity was not significantly different when basal (25.2%) and stimulated (27%) values were compared (P > 0.05), and when mean increments of NG-PRL and G-PRL were compared (345 and 348%, respectively). The opioid drug induced a significant decrease in cortisol levels after injection and during operation (from 585 +/- 63 to 99 +/- 51 nmol/l) with a concomitant decrease in ACTH levels. GH levels were not significantly altered during anaesthesia but were significantly greater (P < 0.05) after than before surgery (5.0 +/- 1.3 vs 0.98 +/- 0.54 mU/l, respectively). CONCLUSIONS: We conclude from the present and from previous data that opioid induced anaesthesia is accompanied by an increase in both glycosylated and non-glycosylated PRL and that different PRL secretagogues may induce distinct responses in terms of PRL molecular forms.

Adult↗

[Pseudovascular laterobulbar syndrome secondary to astrocytoma].

A patient presented with an atypical left lateral medullary syndrome (LMS) mimicking a stroke. Magnetic resonance imaging demonstrated a tumour in the left dorsolateral part of the medulla. Biopsy revealed a grade II astrocytoma. The patient died two weeks after surgery. Nine pathologically verified previous cases of LMS caused by a tumour are reviewed. LMS is invariably atypical because of associated supratentorial or extensive brainstem symptomatology. Onset is usually progressive but stroke-like onset has been occasionally reported. Glial tumours as a cause of LMS are less frequent than metastasis. Successful treatment has been reported in a case of low grade astrocytoma.

Astrocytoma↗

Suprasellar granular-cell tumour, presenting with intraventricular haemorrhage.

A case of suprasellar granular-cell tumour (GCT), presenting with intraventricular haemorrhage is described. The authors emphasize the exceptional character of spontaneous haemorrhage for a GCT, although haemorrhagic state during surgery has often been reported and may hinder total removal. Preoperative arteriography discloses a suprasellar blush in half of the cases. This facilitates the preoperative diagnosis. By taking special preoperative and operative precautions against haemorrhage complete removal can be carried out provided there is no encasement of the optic chiasm.

Cerebral Ventricles↗

[Cerebral infarction in patients aged 16 to 35 years. Prospective study of 52 cases].

OBJECTIVES: Aetiologies of cerebral ischemic events in young adults are various and often contraversial: atherosclerosis plays a role after age 35 years, cardioembolism is often recognized as the major cause, and numerous new predisposing conditions have been described. To evaluate very premature cerebral infarction, we studied prospectively 52 consecutive patients (34 women and 18 men) aged 16-35 years (mean 28.6 +/- 5.6 years) admitted over a 6-year period for an arterial cerebral infarct identified on CT, on MRI or both. METHODS: All patients were investigated using a standard protocol including cerebral angiography, transthoracic echocardiography, 24-hour Holter ECG monitoring, coagulation inhibitors levels, lupus anticoagulant testing, HIV and syphilitic serologies. Additional investigations were performed in a majority of patients: transesophageal echocardiography in 33, contrast echocardiography in 50, and anticardiolipin antibodies levels in 38. RESULTS: The arterial distribution of infarction did not differ from that of overall stroke patients. Sixteen cases were classified as certain aetiologies, including cardiac diseases with high embolic risk (n = 9), spontaneous arterial dissection (n = 4), moya-moya disease (n = 1), atherosclerosis (n = 1), and inherited antithrombine III deficiency (n = 1). Eighteen cases were classified as possible aetiologies including cardiac diseases with low embolic risk (n = 11) such as mitral valve prolapse or atrial septal aneurysm, miscellaneaous arteriopathies (n = 3) such as arterial dysplasia, antiphospholipid antibodies syndrome (n = 1) and migrainous stroke (n = 3). The 18 last cases were classified as unknown aetiologies, despite all patients but one had at least one vascular risk factor: this group significantly differed from the formers in that the patients were more frequently women using oral contraceptive associated with tobacco consumption, hypercholesterolemia, or both. Two patients died acutely and the survivors were followed 31 +/- 18 months. Three patients experienced recurrent stroke. Functional outcome was assessed using the Rankin scale on admission and 6 to 12 months after the onset of stroke: patients evaluated < or = 2 (no to mild handicap) were 31% on admission and 82% after recovery. Twenty six p. cent remained unable to resume a work. CONCLUSION: Despite extensive evaluation, identification and classification of aetiologies of cerebral infarction in young adults should be cautious because the risk as well as the pathogenesis of many potential causes still need to be defined.

Adolescent↗

Detection of i(17q) chromosome by fluorescent in situ hybridization (FISH) with interphase nuclei in medulloblastoma.

Medulloblastomas are the most frequent primitive neurectodermal tumors in children. An isochromosome for the long arm of 17, i(17q), is found in 30% of medulloblastomas. For some authors, this abnormality is observed in cases with a shorter survival time. In our cytogenetic studies of 30 medulloblastomas, we observed i(17q) in only three cases, a monosomy 17 in two cases, a monosomy 22 in four cases, nonspecific numerical or structural abnormalities in five cases, and normal karyotypes in 12 cases. We compared the results of karyotypic analysis after culture and FISH with a chromosome 17 alpha satellite DNA probe on interphase nuclei in five cases of medulloblastoma. In one case, i(17q) was only observed in four cells in karyotypic analysis, in three cases a normal karyotype was found, and in one case karyotypic analysis was impossible. In all of these cases, i(17q) was observed in a great number of nuclei by FISH on interphase nuclei. Our study shows that the FISH on interphase nuclei permitted us to observe i(17q) in the cases where it was not or could not be completely detected by karyotypic analysis. The association of these two techniques is required to detect i(17q), an abnormality whose prognosis value in medulloblastomas is now recognized.

Adolescent↗

Energy expenditure and withdrawal of sedation in severe head-injured patients.

OBJECTIVES: To determine the outcome of oxygen consumption (VO2) and energy expenditure after cessation of sedation in severe head-injured patients and to assess its usefulness as a predictor of neurologic severity. DESIGN: Prospective, descriptive study. SETTING: Neurosurgical intensive care unit (ICU) in a university hospital. PATIENTS: Fifteen severe head-injured patients with tracheostomies and who were mechanically ventilated and sedated at the time of the study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: VO2 and energy expenditure were measured, using indirect calorimetry during and after discontinuation of sedation. After the measurement period, the patients were divided into two groups. Group 1 included patients who were completely weaned from sedation; group 2 included patients who had to be sedated again using predetermined criteria. In both groups, energy expenditure was close to basal energy expenditure during sedation, and increased to 150% of basal energy expenditure during the recovery period, with maximum hourly values 80% above basal energy expenditure. In group 1, VO2 and energy expenditure changed from 284 +/- 44 mL/min and 1833 +/- 261 kcal/day during sedation to 390 +/- 85 mL/min and 2512 +/- 486 kcal/day for the period without sedation. During this period, there was a significant correlation between VO2 and mean arterial pressure. For the recovery period, there was no difference in mean or maximum VO2 between the two groups of patients. At 24 and 48 hrs after cessation of sedation, VO2 and energy expenditure decrease to 30% above basal energy expenditure. These changes may be due to the recovery of muscular activity, weaning from mechanical ventilation, or an increase in the amount of circulating catecholamines. CONCLUSION: In severe head-injured patients, during the first 12 hrs after the discontinuation of sedation, the patients experienced a large increase in VO2, energy expenditure, and mean arterial pressure. Although these changes have no prognostic value in our study, they have potential deleterious effects in head-injured patients. Methods that blunt these changes which have proven efficacious in anesthesia may be effective for intensive care patients.

Acute Disease↗

Platelet-derived growth factor (PDGF) and receptor (PDGFR) expression in human meningiomas: correlations with clinicopathological features and cytogenetic analysis.

PDGFs and their receptors expression were examined in a series of 46 meningiomas by using specific monoclonal antibodies. The immunostaining was quantified by an image analyser and the results correlated with clinical and morphological data (histological type and grade). In addition, since the PDGFB chain is encoded by the c-sis proto-oncogene localized on chromosome 22 and because monosomy 22 has been frequently reported in meningiomas, PDGFs and PDGFRs expression have been correlated with cytogenetic analysis performed in 29 cases. The results demonstrate PDGF A and PDGF B expression in most meningioma specimens and co-expression of these growth factors in numerous cells. PDGF A and B immunoreactivity was related to histological grade. PDGFR beta expression was strong in almost all meningiomas whereas PDGFR alpha was low. PDGFR alpha expression was related to tumour location and grade and PDGFR beta to histological subtype only. The cytogenetic analysis was not related to PDGFB chain expression. Taken together these data further confirm PDGF and PDGFR expression in human meningioma; PDGF may exist as an heterodimer (AB) as well as its receptor. The lack of correlation between cytogenetic analysis and PDGF values, the low level of PDGFB in recurrent meningiomas suggests that it is unlikely that the c-sis proto-oncogene plays an important role in the genesis of meningiomas.

Adult↗

Ectopic basisphenoidal craniopharyngioma: case report and review of the literature.

We report the case of a patient with a nasopharyngeal craniopharyngioma. The presenting symptoms included a diminished visual acuity, a dysmorphic syndrome, and impaired endocrine function. The computed tomography and magnetic resonance imaging scans showed a partially cystic tumor that had destroyed most of the craniofacial sinus and anterior part of the cranial base. The patient was operated on through a rhinoseptal approach. We found 14 similar cases in the available neurosurgical and otorhinolaryngologic literature. The pathogenesis of this tumor and more especially its origin from Rathke's pouch remnants or pharyngeal hypophysis are discussed.

Adult↗

Cavernous angiomas and arteriovenous malformations of the spinal epidural space: report of 11 cases.

We have retrospectively studied 11 cases of solitary cavernous and arteriovenous malformations of the spinal epidural space. The acute or subacute onset of symptoms was found in all cases, with a neurological deficit in five cases. A plain x-ray study revealed abnormal calcification in one case. Hyperdensity with no iodine enhancement was found on computed tomographic scans in all cases. Magnetic resonance imaging studies showed ovoid or round lesions with isosignal and gadolinium enhancement on T1-weighted images and hypersignal on T2-weighted images, except in one case with hypersignal on T1 and T2 before the administration of a contrast medium. Four lumbar cases were localized in the posterior vertebral ligament; all the thoracic cases were posterior with foraminal extension. The other cases were anterolateral. The surgical findings revealed a dark vascularized epidural lesion associated in two cases with a localized epidural hematoma. A pathological examination revealed seven cavernous angiomas and four arteriovenous malformations. These arteriovenous malformations were all lumbar, and two of four localized within the posterior ligament. The pathophysiology of these vascular malformations is discussed. In light of the good postoperative prognosis of these lesions, surgical removal is recommended for all the symptomatic cases.

Adult↗