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Biomedical subjects

V Albanese

Publications and source records attributed to V Albanese.

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

Arachidonate transport through the blood-retina and blood-brain barrier of the rat after reperfusion of varying duration following complete cerebral ischemia.

The permeability-surface area product (PS) of [1-14C]arachidonate at the blood-retina and blood-brain barrier was determined by short carotid perfusion in young Wistar rats 1 or 6 h after recovery period following complete cerebral ischemia induced by temporary cardiac arrest. For the retina and structures of visual system, hypothalamus and olfactory bulb there was no significant difference over sham-operated rats among mean PSs. For cortex, hippocampus and striatum, significant increases were found at both time intervals of recovery after cardiac arrest. The ischemia-reperfusion model was characterized by a significant increase in tissue conjugated diene in the hippocampus and microsomal lysophosphatidylcholine acyltransferase activity in the cortex. Consistent with these findings, we also show ultrastructural evidence mainly represented by partial opening of interendothelial junctions and mild signs of tissue edema in surrounding neuropil, suggesting barrier leakiness predominantly in the cortex, hippocampus and striatum but almost absent in the retina microvessels. Our results indicate that ischemia-reperfusion does affect influex through blood-brain barrier into regional structures of rat central nervous system of arachidonate, a metabolic substrate and lipid mediator rapidly incorporated into microcapillary and brain lipids. The data also suggested that: (i) reactive oxyradicals were moderately generated during the early phase of ischemic-reperfusion process in the rat; (ii) after reperfusion, in vitro susceptibility of different brain regions to iron-induced peroxidation was highest in the hippocampus and lowest in the cortex and striatum; (iii) membrane phospholipid repair mechanisms were activated at the same time.

Acyltransferases↗
PubMed1998

AMPA receptor subunits are differentially expressed in parvalbumin- and calretinin-positive neurons of the rat hippocampus.

Recent studies suggest a functional diversity of native alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate-type glutamate receptor channels (AMPARs). In several types of interneurons, AMPARs are characterized by higher Ca2+ permeability and faster kinetics than AMPARs in principal cells. We studied the expression profile of AMPAR subunits in the hippocampal parvalbumin (PV)- and calretinin (CR)-positive cells, which represent different populations of non-principal cells. To this end, non-radioactive in situ hybridization with AMPAR subunit specific cRNAs was combined with immunocytochemistry for PV or CR. Double-immunolabelling using antibodies against AMPAR subunits and PV or CR was also performed. PV-containing neurons represent a fairly homogeneous population of cells expressing high levels of GluR-A and GluR-D mRNAs, moderate levels of GluR-C and low levels of GluR-B mRNAs in all the examined regions of hippocampus. The vast majority of CR-containing cells have a much lower expression of GluR-A, -C and -D mRNA than PV-positive neurons, although similarly featuring low levels of GluR-B mRNA. Only a subpopulation of CR-containing cells, the spiny neurons of the dentate gyrus and CA3 region of the hippocampus were characterized by a strong expression of GluR-A and -D subunit mRNAs. The differential pattern found for the AMPAR subunit mRNA expression was confirmed by immunocytochemistry at protein level. Despite the common feature of low GluR-B subunit expression, PV- and CR-containing interneurons differ with respect to the density and combination of their expressed AMPAR subunits. The different combination of subunits might subserve different properties of the AMPA channels featured by these cell types, with implications for the functioning of the hippocampal network.

Animals↗
PubMed1997

Metabotropic glutamate receptor expression in cultured rat astrocytes and human gliomas.

In order to confirm the existence of metabotropic glutamate receptors in astroglial cultures and to provide information on different receptor subtypes, the expression of different mGluRs was analysed in cultures highly enriched in rat astroglial cells. mRNA levels for mGluR1, 2, 3, 4, 7 were undetectable by Northern blot analysis in primary type-1 astroglial cultures derived from total cerebral hemispheres, cerebral cortex and striatum. Interestingly, these cultures expressed a low, but detectable, level of mGluR5 mRNA. The more sensitive technique Reverse Transcription-Polymerase Chain Reaction (RT-PCR) confirmed the presence of mGluR5 transcript in cultured astrocytes and, in addition, revealed the presence of mGluR3 mRNA. The lack of expression of mGluR5 in CG-4 cells, a rat cell line able to differentiate in type-2 astrocytes or oligodendrocytes depending on the culture conditions, suggested that the presence of mGluR5 was not a general feature of cells of glial origin. Moreover, all the examined mGluR transcript were undetectable by RT-PCR in CG4 cells. In order to confirm the possible expression of mGluR5 in cell of glial origin we examined the mRNA levels for this receptor in tissue samples from human gliomas obtained after surgical resection of the tumors: only 1 sample (grade II astrocytoma), out of 8 examined, showed the presence of mGluR5 mRNA. In conclusion our data show that the only cloned metabotropic receptor linked to phosphoinositide hydrolysis, whose expression is detectable in cultured type-1 astrocytes, in mGluR5. It remains to be established if the low level of expression of mGluR3 could be responsible for the group II metabotropic glutamate receptor activity previously observed in cultured astroglial cells.

Animals↗
PubMed1997

A neural-specific hypomethylated domain in the 5' flanking region of the glial fibrillary acidic protein gene.

In the present study we examined the methylation status of the glial fibrillary acidic protein (GFAP) gene promoter, analyzing various CG sites in both the human and rat gene in GFAP-expressing and nonexpressing tissues. Moreover, we studied the methylation of specific CG sites in different rat brain areas during postnatal development, in cell cultures highly enriched in specific neural- or non-neural-cell types (fibroblasts), and in human gliomas. The obtained results do not support a simple correlation between demethylation and expression of the GFAP gene but help to identify a cluster of CG sites in the 5'flanking region (from -1176 to -1471 in the rat) that are hypomethylated in neural cell types and localized in a region highly conserved between rat, mouse and human GFAP promoters. Neural-specific hypomethylation of this conserved zone can be observed also in the human GFAP gene both in normal brain tissue and neoplastic glial cells. A higher demethylation of the -1176 site at early stage of postnatal life was observed in specific rat brain areas, such as hippocampus and cerebellum. The most dramatic differences were observed in the cerebellum where a peak of demethylation of the -1176 site was detected at 15 days of postnatal life, followed by an intense remethylation of this site. Results of experiments in the CG4 glial progenitor cell line showed that demethylation of the -1176 site is already established before transcriptional activation of the GFAP gene. Moreover, results of experiments in primary cell cultures show that in neuronal cell types, such as cerebellar granule cells and embryonic cerebral hemisphere neurons, the level of demethylation of the -1176 site is comparable to that observed in cultured astrocytes. In contrast a high level of methylation can be observed in cultured non-neural cell types (fibroblasts). Such neural-specific hypomethylation could be established in a very early stage in the progression along the neural cell lineage and could play a role in maintaining a local open chromatin conformation which is then necessary to allow the interaction with specific regulatory factors present in astroglial cells.

Animals↗
PubMed1997

Traumatic chronic subdural hematoma over 80 years. A preliminary prospective study.

Six very elderly patients (mean of age: 85 years with range from 80 to 95 years) with mean GCS = 12 and mean clinical grade = 2.5 affected by traumatic chronic subdural hematoma (CT mean maximum thickness = 2.8 +/- 0.46 cm with midline shift = 1.56 +/- 0.48 cm and absence of homolateral mesencefalic cistern in all case but one) underwent parietal or frontal craniectomy under temporalis muscle and 48-h closed subdural drain. There was no mortality as consequence of the operative procedure. In all the patients but one who died postoperatively from a preoperative midbrain infarction secondary to a transtentorial herniation, there was a progressive and slow clinical improvement in spite of residual markedly persistent fluid collection (CT mean maximum thickness 1.44 +/- 0.19 cm) with mass effect (CT mean midline shift = 0.5 +/- 0.17 cm) due to a some failure of the brain to re-expand. Impairment of hemodynamic reserve should be considered as important cause of failure of the brain re-expansion. Clinical and CT control within two months after discharge from hospital demonstrated further clinical improvement (mean GOS = 4.6) and resolution of subdural residual fluid collection. Basing on these results we recommend do not reoperate persistent subdural fluid collection if there is clinical improvement. The patient can be discharged from hospital or transferred to Geriatric Department where he can be clinically and CT evaluated. Only a clinical deterioration or an increase of residual subdural fluid collection provides clear indication to reoperative surgery.

Aged↗
PubMed1997

Painful ophthalmoplegia syndrome (spheno-cavernous syndrome) caused by a ruptured posterior communicating artery aneurysm. A brief report.

A case is reported of ruptured posterior communicating artery aneurysm presenting as a painful ophthalmoplegia syndrome (spheno-cavernous syndrome). This case suggests that there is need to carried out immediately neuroradiological studies when a painful ophthalmoplegia appears because of possible underlying intracranial aneurysm. This decisional algorithm should decrease the probability of aneurysmal rebleeding and increase the chance of oculomotor nerve function recovery.

Aneurysm, Ruptured↗
PubMed1997

Concurrent trigeminal and glossopharyngeal neuralgia, hemifacial spasm and hypertension by neurovascular compression. Case report.

The case is reported of a 58 year-old man with left-sided trigeminal and glossopharyngeal neuralgia, left hemifacial spasm and arterial hypertension. Preoperative MRI angiography examination showed a massively ectatic left vertebral artery. At operation a multiple neurovascular compression, which is described, was discovered. Microvascular decompression was performed and postoperatively the patient had complete relief from the trigeminal and glossopharyngeal neuralgia, from the hemifacial spasm, and has sustained normal arterial pressure without medication. The value of MRI in diagnosing of neurovascular compression syndromes and pathophysiology of the "so called" arterial hypertension are discussed.

Cerebral Angiography↗
PubMed1997

Infected cerebral hemorrhage by ruptured infectious anterior communicating artery giant aneurysm in a patient with T cell acute lymphoblastic leukemia. Case report.

Although the majority of infectious (bacterial) intracranial aneurysms occur in patients with subacute bacterial endocarditis, septic cerebral embolization and infectious intracranial aneurysm formation can also occur in immunocompromised patients. We report the case of ruptured bacterial aneurysm occurring in a 19 years old man immunocompromised by vigorously treated acute lymphoblastic leukemia. This case confirms very poor prognosis for infectious aneurysms in immunocompromised patient reported in literature, suggesting that a high index of suspicion needs for early diagnosis and that a conservative approach (high dose antibiotic therapy with possible delayed surgery) should be preferred unless intracerebral hemorrhage or abscess with significant mass effect provides a clear indication for operative intervention.

Adult↗
PubMed1996

Arachidonate transport through the blood-retina and blood-brain barrier of the rat during aging.

The permeability-surface area product (PS) of [I-14C]arachidonate at the blood-retina (BRB) and blood-brain barrier (BBB) was determined after short carotid perfusion in Wistar rats at 4, 12 and 28 months of age. For the visual system structures, parietal and frontal cortex, striatum, hypothalamus, hippocampus and olfactory bulb there was no significant difference among mean PSs in any age group. Our results indicate that: (1) arachidonate is able to cross at relevant rate BRB and BBB; (2) in all brain regions except retina, optic tract and hippocampus, blood barriers have a transport capacity for arachidonate significantly higher than that for docosahexaenoate and palmitate as well; (3) aging does not affect influx into retina and other structures of rat central nervous system of the arachidonate, a metabolic substrate rapidly incorporated into microcapillary and brain lipids, and for which simple diffusion transport across the BRB and BBB may be postulated.

Aging↗
PubMed1996

Phosphatidylcholine synthesis-related enzyme activities of bovine brain microvessels exhibit susceptibility to peroxidation.

In microvessels isolated from bovine brain, microsomal enzyme activities involved in phosphatidylcholine biosynthesis and degradation were determined. The microvessels possessed acyl-CoA:1-acyl-sn-glycero-3-phosphocholine (AT) and glycerophosphocholine phosphodiesterase (GroPChoPDE) activity at a higher level compared with bovine and rat brain or rat liver microsomes whereas they expressed CTP:phosphocholine cytidylyltransferase (CT) and choline phosphotransferase (CPT) activity at a lower level. Each enzyme has been characterized in terms of response to inhibitors or activators revealing properties very similar to those in brain and liver microsomes. In the homogenate prepared from t-butylhydroperoxide-treated microvessels (10 min exposure to 10 microM up to 1 mM concentrations), AT and CPT activities exhibited a significant dose-dependent inhibition. In contrast, GroPChoPDE activity was unaffected. CT was inhibited only at 1 mM concentration. Short treatment of microvessels with Fe2+ (20 microM)-ascorbate (0.25 mM) or 100 microM linoleate hydroperoxide did not have any effect on the activity of the four enzymes. Strong inhibition of all enzymes was noted when the linoleate hydroperoxide system was fortified by Fe2+ ions (100 microM). AT inactivation was also found when oxidized low density lipoprotein was preincubated with microvessels. On the other hand, oxidized LDL left unchanged CPT and GroPChoPDE activities whereas it promoted a slight stimulation of cytidylyltransferase activity. Overall, the results suggest a link between oxygen radical generation and the perturbation of the microvessel membrane structure in which the four enzymes are incorporated, coupled to a direct sulfhydryl protein modification.

Animals↗
PubMed1996

Ossifying fibroma of the skull in a patient with neurofibromatosis type 1. Case report.

Ossifying fibroma is a rare, benign, primary bone tumor that occurs most commonly in the mandible; a cranial vault location is extremely rare. In this report a case of symptomatic frontoparietotemporal ossifying fibroma with intracranial growth and cerebral displacement in a 12-year-old boy with neurofibromatosis type 1 (NF1) is described. Once excised the lesion did not recur. The skeletal system is frequently affected in NF1, and bone abnormalities are present in 50% to 70% of patients with this condition. The etiology of such lesions in NF1 is still controversial. To the authors' knowledge, ossifying fibromas of calvarial bones have not been described in NF1.

Child↗
PubMed1995

Thallium-201-SPECT and 99Tc-HM-PAO SPECT imaging to study functionally cerebral supratentorial neoplasms: the biological basis of the functional imaging interpretation.

Nineteen patients with histologically diagnosed supratentorial cerebral neoplasms carried out CT and/or MRI, 201T1 SPECT and 99mTc-HM-PAO studies preoperatively. 99mTc-HM-PAO SPECT images revealed information about both tumoral perfusion and intracellular concentration of mediators converting 99mTc-HM-PAO to hydrophilic derivates (glutathione and other yet unknown factors) within viable tumoral cells while 201T1 SPECT images about permeability, extension of tumoral capillary network and viable tumoral cells presence. Basing on the different mechanisms of the tracer uptake, cerebral supratentorial tumors could be distinguished in three groups: 1) cerebral tumors presenting 201T1 very high uptake (201T1 index > 1.5) and homogeneous and high retention of 99mTc-HM-PAO (CBI > or = 1.05) (meningiomas, PRL adenoma); histologically these neoplasms presented very rich neoformed capillary network; 2) cerebral neoplasms with 201T1 high uptake (201T1 index > 1.5) and with inhomogeneous retention of 99Tc-HM-PAO (high grade gliomas amd metastasis); microscopically these tumors presented vascular proliferation, necrosis and high cellularity; 3) cerebral neoplasms characterized by 201T1 low uptake (201T1 index < 1.5) and lower retention of 99Tc-HM-PAO than cerebellum (low grade gliomas); at microscopic examination these neoplasms were characterized by absence of vascular proliferation and necrosis. These results suggest coupled 201T1/99Tc-HM-PAO SPECT is necessary to discriminate intra-axial from extra-axial tumor localization (lacking CT or MRI) and to detect the grade of malignancy of gliomas and tumor cell presence within necrotic areas.

Adult↗
PubMed1995

Parietal bone non-secreting solitary myeloma (plasmacytoma) with spread to the epidural space and scalp. Case report.

A case of solitary osteolytic lesion in the parietal bone in an otherwise asymptomatic patient is reported. Skull radiographs showed a radio-lucent lesion with well-defined margins without sclerotic reaction, CT scan demonstrated a mass that markedly enhanced extending from the epidural to the subcutaneous space of the parietal region. The patient underwent surgery and tumor was completely excised. Pathological examination showed tumor to be a plasmacytoma synthesizing kappa chains. Postoperatively the patient received radiotherapy. Four years after treatment there was no sign of local recurrence on CT can and of progression of multiple myeloma on clinical and laboratory studies. Our recommended treatment is that of a complete surgical excision followed by radiation to dose levels of 45-50 Gy. The patients should be followed carefully because of either local recurrence or possible progression to multiple myeloma. Radiotherapy and chemotherapy should started when signs of progression or other significant disease manifestations occur.

Aged↗
PubMed1994

Foramen magnum stenosis and bilateral benign subdural collections in achondroplasia: case report.

A case of achondroplasia is presented in which cervico-medullary junction compression by foramen magnum stenosis and generalized seizures by bilateral subdural effusions were relieved by suboccipital craniectomy with C1 laminectomy and drainage of the collections. The important role played by NMR in the diagnosis of foramen magnum stenosis is stressed; the possible causes of hydrocephalus and subdural collections in achondroplasic patients are discussed. According to the authors surgical drainage of benign subdural collections in these patients is indicated in case of intractable seizures.

Achondroplasia↗
PubMed1994

Intramedullary spinal neurinoma: case report and review of 46 cases.

A case of intramedullary neurinoma of the cervical spinal cord in a patient with no sign of von Recklinghausen's disease is reported. This case was diagnosed by computed tomography and magnetic resonance imaging and treated surgically. The literature covering 46 other cases is reviewed. The discussion, examines the possible etiology, the role of diagnostic procedures and the difficulties of the surgical treatment of these tumors.

Female↗