PubMed Health⌕ Search

Biomedical subjects

R Pisani

Publications and source records attributed to R Pisani.

At least 19 recordsLinked to original sources
PubMed2005

Functionally independent subunits in the oligomeric structure of the GABA cotransporter rGAT1.

We have combined structural and functional approaches to investigate the role of oligomerization in the operation of the GABA transporter rGAT1. Xenopus laevis oocytes were induced to express, either separately or simultaneously, the wild-type form of rGAT1 and a mutated (Y140W) form, unable to translocate GABA and to generate transport currents, although its intramembrane charge movement properties are only slightly affected. These characteristics, together with the insensitivity of Y140W to the blocking action of SKF89976A, were used to study the possible functional interaction of the two forms in an heteromeric structure. The electrophysiological data from oocytes coexpressing wild-type and Y140W rGAT1 were consistent with a completely independent activity of the two forms. Oligomerization was also studied by fluorescence resonance energy transfer (FRET) in tsA201 cells expressing the transporters fused with cyan and yellow fluorescent proteins (ECFP and EYFP). All combinations tested (WT-ECFP/WTEYFP, Y140W-ECFP/Y140W-EYFP and WT-ECFP/ Y140W-EYFP) were able to give rise to FRET, confirming the formation of homo- as well as heterooligomers. We conclude that, although rGAT1 undergoes structural oligomerization, each monomer operates independently.

Animals↗
PubMed2004

Removal of sulfur dioxide from a continuously operated binary fluidized bed reactor using inert solids and hydrated lime.

Sulfur dioxide pollutant was treated in the laboratory with hydrated lime particles having a mean diameter of 9.1 microm in a continuously operating binary fluidized bed reactor also containing inert sand particles with sizes varying from 500 to 590 microm. The influence of temperature (500, 600, 700 and 800 degrees C) on the reaction medium, of the superficial velocity of the gas (0.8, 1.0 and 1.2 m/s), and of the Ca/S molar ratio (1, 2 and 3) on the SO2 removal efficiency were investigated for an inflow gas concentration of 1000 ppm and an initially static bed height of 10.0 cm. The pollutant removal efficiency proved to depend on the temperature and the velocity of the gaseous flow and was strongly influenced by the Ca/S molar ratio. The maximum efficiency of 97.7% was achieved at a temperature of 700 degrees C, a Ca/S ratio of 3 and a velocity of 0.8 m/s. The lime particles' mean residence time was determined by an indirect method, which consisted of integrating the gas concentration curves normalized with respect to time. Based on a calculation of the critical transition velocities, it was concluded that the reactor operated in a bubbling regime under each condition investigated here.

Calcium Compounds↗
PubMed2001

Delayed effects of a migrated foreign body (sewing needle) in the cervical spine: a case report.

STUDY DESIGN: A case report is presented. OBJECTIVE: This report documents one case of intraspinal migration of a metal foreign body. SUMMARY OF BACKGROUND DATA: The migration and penetration of foreign bodies into the spine have been described, but there are only three reports of a needle as the causative object. METHODS: This case report included a chart review, an examination of the patient, and a literature search. RESULTS: The patient successfully underwent surgery, in which the foreign body (a sewing needle) was removed. CONCLUSION: It is important to be aware of the possible delayed penetration of a foreign body into the spine even in patients with few or no symptoms.

Adult↗
PubMed1999

Thoracic epidural hematoma after spinal manipulation therapy.

Posttraumatic spinal epidural hematoma is an unusual pathology. The authors report the case of a 64-year-old woman who experienced thoracic epidural hematoma during a session of spinal manipulation therapy (SMT). In the literature, such an event has been reported previously only twice. This case represents the first spinal epidural hematoma occurring after a chiropractic manipulation in the lumbar region. Surgical evacuation of the spinal hematoma resulted in complete recovery in the patient. Complications of SMT are reviewed, and the etiology and features of spinal epidural hematoma are discussed.

Female↗
PubMed1998

Intracranial insertion of a nasogastric tube in a case of homicidal head trauma.

A case of accidental intracranial penetration of a 29-cm-long portion of nasogastric tube (NGT) in a 27-year-old female victim of a severe homicidal skull and brain trauma is reported. Accidental penetration of the NGT occurred through a large fracture of the ethmoid lamina cribrosa. In addition to a systematic review of previously reported cases, circumstantial data, clinical aspects, and autopsy data have been analyzed to draw medicolegal considerations concerning the connection between death and insertion of an NGT, which may also contribute to the ascertaining of any possible professional responsibility of medical staff, in a case fraught with numerous legal complications.

Adult↗
PubMed1997

Entrapment neuropathy of the internal pudendal nerve. Report of two cases.

Entrapment neuropathy of the internal pudendal nerve in the Alcock canal is a rare entity and literature on the subject is lacking. The pathogenesis of this disease is probably related to repeated microtraumatisms of the perineal region acting on the Alcock canal or dysmetabolic diseases favouring compression of the pudendal nerve inside the Alcock canal. In this article two new cases which have come to our attention are described and literature on the topic, with special regard to diagnosis and treatment, is reviewed.

Autonomic Nerve Block↗
PubMed1996

Cerebral haemodynamic changes induced by spinal cord stimulation in man.

Spinal cord stimulation (SCS) has been shown to influence cerebral perfusion in both experimental models and humans. With the aim of further verifying such an effect, twelve patients had an epidural (cervical or dorsal) lead inserted percutaneously and underwent regional cerebral blood flow (rCBF) examinations (133-Xenon inhalation method) before and during SCS. Mean blood velocity (MBV) in the middle cerebral artery was also measured in seven cases by means of transcranial Doppler. In the patients with a cervical lead, a symmetrical increase in rCBF was found, mainly in the anterior regions (from +8% to +21%). MBV increased in four cervical lead implants (from +16% to +20%) and in one case with a dorsal lead (+15%). These results suggest that cerebral perfusion may increase in patients undergoing SCS through a cervical lead. Although the mechanism involved in the increase in rCBF remains to be clarified, frontal lobe functional activation by the ascending reticular pathways through the thalamo-cortical projections might be hypothesised.

Adolescent↗
PubMed1996

Study on aneuploidy and p53 mutations in astrocytomas.

To determine whether a correlation exists between aneuploidy and p53 status in astrocytic tumors we analyzed 48 astrocytomas with different grades of malignancy for the presence of p53 mutations and aneuploidy of chromosomes 10 and 17 (Ch10, Ch17), known to be particularly involved with this type of tumor. We used polymerase chain reaction (PCR)-based denaturing gradient gel electrophoresis (DGGE) analysis on exons 5-8 of the p53 gene, and fluorescence in situ hybridization (FISH) analysis on interphase nuclei using chromosome specific pericentromeric probes, respectively. Our results showed that Ch10/Ch17 aneuploidy is a common early event in astrocytomas (90% of low grade tumors are aneuploid). p53 mutations and Ch17 aneuploidy are early events, but their incidence is not dependent on tumor grade. Loss of Ch10 is the only alteration that significantly correlates with tumor progression. No significant correlation between the presence of Ch10/Ch17 aneuploidy and p53 mutations was found. However, the coexistence of p53 mutations and aneuploidy, was observed in a subset of cases. The presence of p53 mutations appeared to be a significant predictor of a poor prognosis. In conclusion, genomic instability may or may not be associated with p53 mutations in astrocytomas, thus suggesting that other cellular determinants can also be responsible for the aneuploidy observed.

Adult↗
PubMed1996

Third ventricular meningiomas of infancy. A case report.

Intraventricular location of meningiomas is impressively higher in childhood and adolescence than in adult patients, respectively 15 to 22% versus 0.2 to 4%. However, location of this tumor within the third ventricle is extremely rare in the pediatric population, since, as far as we know, 17 cases have been reported so far. A case of meningioma of the third ventricle in a 9-year-old boy and its clinical and pathological finding are discussed.

Cerebral Ventricle Neoplasms↗
PubMed1996

Cauda equina metastasis from ovarian malignancy.

SUMMARY: A case of cauda equina metastasis from ovarian serous papillary adenocarcinoma in a 51-year-old patient is reported. The clinical significance and different hypotheses on the metastatic route to the spine are discussed.

Cauda Equina↗
PubMed1996

Multi-layer neural network analysis of cerebrospinal fluid pressure patterns in idiopathic normal-pressure hydrocephalus.

The cerebrospinal fluid (CSF) pressure patterns have been reported as one of the most relevant indexes for the diagnosis and treatment of idiopathic normal-pressure hydrocephalus (INPH). Forty consecutive patients coming from our observations with the classic Hakim's triad underwent continuous CSF pressure monitoring via lumbar puncture for at least 12 hours. Twenty-eight patients were diagnosed as having INPH and underwent CSF shunt. A multi-layer neural network (perceptron) was employed to study the pressure patterns in order to try an alternative classification to the "expert" neurosurgeon one. Differences between expert and neural network classifications were indeed observed. Such differences may depend on the small group studied or on the inadequacy of CFS pressure patterns in correctly individuating those INPH patients who benefit from shunt surgery. The authors think that neural network processing of INPH could add relevant information to select the "responder" patients to surgery: in fact neural networks represent a powerful methodology for aiding the expert to select the proper choice on the basis of "what learnt" by the networks themselves.

Cerebrospinal Fluid↗
PubMed1995

Acute intracranial epidural haematoma in a basketball player: a case report.

A 35-year-old basketball player suffered a serious double head injury during a match. An acute left temporal epidural haematoma, which necessitated surgical drainage, developed. The exceptional circumstances of the trauma are discussed and the literature concerning basketball-related injuries is reviewed.

Adult↗
PubMed1995

Assessment of regional cerebral blood flow during spinal cord stimulation in humans.

Increased cerebral perfusion has been reported in both animal models and humans undergoing spinal cord stimulation (SCS). However, this was an inconsistent finding and variables able to influence regional cerebral blood flow (rCBF) following SCS are poorly investigated. We report our experience on rCBF measurements by the xenon-133 inhalation technique in 20 patients receiving acute and chronic SCS for different pathologies in basal conditions. Neither acute nor chronic SCS induced significant rCBF changes in the group of patients as a whole. However females, non-atherosclerotic patients and patients with a cervical SCS lead, showed a trend (borderline statistical significance) toward a redistribution of rCBF with increased values in frontoprerolandic and decreased values in postrolandic regions. Although SCS appears to influence intracerebral distribution more than absolute changes in blood flow, the mechanisms underlying such a phenomenon remain unknown. Functional activation of frontal lobes by the ascending reticular pathways through the thalamofrontal projections could be one possible hypothesis which has to be confirmed by further studies.

Administration, Inhalation↗
PubMed1994

Cerebral blood flow and somatosensory evoked response changes induced by spinal cord stimulation: preliminary follow-up observations.

A group of 6 patients undergoing cervical spinal cord stimulation (SCS) because of different pathologies was studied. Multipolar leads (QUAD-Medtronic) were inserted percutaneously; following an SCS test period, leads were connected to a multiprogrammable, fully implantable generator (ITREL II). Neither surgical nor other side effects were found. Regional cerebral blood flow (rCBF) (xenon-133 inhalation) was determined in the basal condition and after 30 min of SCS. Somatosensory-evoked potential (SSERs) from the legs were recorded in basal conditions and after 45 min of SCS. In 2 patients SSERs could not be evaluated due to electrical noise from SCS. CBF increased mainly in anterior regions in 4/6 patients (P300 improved in 1 of them and in another case), and was unchanged in 2 patients. rCBF was retested after a mean of 9.5 months of continuous SCS with the same parameters. rCBF returned to basal values in the 4 patients showing an early flow increase; in contrast, rCBF increased in the other 2 cases without early flow changes. These preliminary data seem to support the view of an acute effect of SCS on rCBF as well as on SSER, at least in some patients. Differences in long-term rCBF modifications might depend on either the underlying pathology or on the different neuronal system involved by SCS.

Adolescent↗
PubMed1991

[Endoscopic sclerotherapy of esophageal varices].

Magnetic tape recordings of endoscopic images relating to pathologies with it is extremely important to follow morphological changes after treatment offer unquestionable advantages especially in the field of sclerosing endoscopic therapy for esophageal varices. This study--which was carried out using a 3/4 inch U-Matic videotape lasting 10 minutes--confirm the above statement. The criteria of selection for sclerosing techniques are illustrated according to the authors' personal evaluations made on the basis of experience accumulated during more than 10 years' activity; the results of modulated treatment are compared as both emergency and elective treatment, used as the single therapy or following deconnection or portosystemic derivation operations. The choices are confirmed by the number of successful outcomes, with only minimal and almost always easily controlled complications. This has led to the method's inclusion in clinical practice as yet another means of controlling hemorrhages due to portal hypertension, in addition to permitting a marked increase in the percentage of success following deconnecting and derivative operations performed in patients in better conditions of clinical compensation.

Endoscopy↗
PubMed1991

"Unusual" MRI appearance of sphenoid sinus mucocele.

The authors report a case of sphenoid sinus mucocele which exhibited unusual MRI features. However a review of the literature shows that these lesions may present with different MRI appearances probably related to the variability of the cyst content. Further series are needed for a better definition of the MRI behaviour of the lesions.

Adult↗