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Biomedical subjects

C Giorgi

Publications and source records attributed to C Giorgi.

At least 19 recordsLinked to original sources
PubMed1997

Organization of the M genomic segment of Toscana phlebovirus.

The nucleotide sequence of the Toscana (TOS) virus M RNA segment contains a single major open reading frame in the viral-complementary sequence, which can encode a polyprotein of 1339 amino acids. To map the TOS M segment product(s), different regions of the putative M polypeptide were expressed as glutathione S-transferase fusion proteins, which were purified and inoculated into mice to produce hyperimmune sera. By Western blot analysis, a protein of approximately 30 kDa and two glycoproteins, G1 and G2, with the same molecular mass (approximately 65 kDa) were identified in TOS virus-infected cells. The 30 kDa protein, which reacted with antibodies raised to the NH2-terminal, was found to be a non-structural protein (designated NSm). By immunoprecipitation analysis of TOS virus-infected cell lysates, both treated or untreated with tunicamycin, the relative positions of glycoproteins G1 and G2 were determined. The gene order, with respect to the genomic M RNA, was found to be 3' NSm-G1 -G2 5'

Animals↗
PubMed1997

Radiosurgery for cerebral AVMs in children and adolescents: the neurobehavioral outcome.

Eight patients, ranging in age from 9 to 18 years, were treated for arteriovenous malformations using gamma knife radiosurgery and were evaluated an average of 6 years after treatment to record potential effects of radiosurgery on cognitive and neuropsychological performance. Tests for general intelligence, nonverbal intelligence, memory and its components, and attention performance were administered to patients and compared with test results of age-matched siblings or first cousins. No statistically significant difference was found between the performance of patients and controls in any of the tests administered. Additionally, a specially designed questionnaire completed by the patients, their parents, and their teachers revealed that the patients' emotional and relational behavior was stable and unchanged after treatment. No correlation was found between the neurocognitive test performance and the lesion volumes irradiated, but the lesion site was found to contribute to the type of deficit recorded after treatment. The less invasive nature of the radiosurgical approach, combined with the brevity or absence of hospitalization, presumably contributed to the patients successful physical, mental, and emotional recovery.

Adolescent↗
PubMed1996

Inhibition of HIV-1 replication by cyclopentenone prostaglandins in acutely infected human cells. Evidence for a transcriptional block.

Cyclopentenone prostaglandins (PGs) inhibit virus replication in several DNA and RNA virus models, in vitro and in vivo. In the present report we demonstrate that the cyclopentenone prostaglandins PGA(1) and PGJ(2) at nontoxic concentrations can dramatically suppress HIV-1 replication during acute infection in CEM-SS cells. PGs did not affect HIV-1 adsorption, penetration, reverse transcriptase activity nor viral DNA accumulation in HIV-1 infected cells. A dramatic reduction in HIV-1 mRNA levels was detected up to 48-72 h after infection (p.i.) in PG-treated cells, and HIV-1 protein synthesis was greatly reduced by a single PG-treatment up to 96 h p.i. Repeated PGA(1)-treatments were effective in protecting CEM-SS cells by the cytopathic effect of the virus, and in dramatically reducing HIV-1 RNA levels up to 7 d after infection. The antiviral effect was not mediated by alterations in the expression of alpha-, beta-, or gamma-interferon,TNFalpha, TNFbeta, IL6, and IL10 in HIV-infected CEM-SS cells. The fact that prostaglandins are used clinically in the treatment of several diseases, suggests a potential use of cyclopentenone PGs in the treatment of HIV-infection.

Antiviral Agents↗
PubMed1995

Robot-assisted microscope for neurosurgery.

We describe the implementation of a robotic arm connected to a neurosurgical operative microscope. A force feedback sensor drives the motors of the arm in response to the positioning of the microscope by the surgeon. Computer graphic techniques allow tracking of the current position of the microscope within the volumetric reconstruction of the brain. The integration of the prototype into the neurosurgical operating room is currently being evaluated. Preliminary comments on this experimental phase are offered.

Angiography, Digital Subtraction↗
PubMed1994

A computer assisted toolholder to guide surgery in stereotactic space.

A computer assisted toolholder, integrated with an anatomical graphic 3-D rendering programme, is presented. Stereotactic neuroanatomical images are acquired, and the same reference system is employed to represent the position of the toolholder on the monitor. The surgeon can check the orientation of different approach trajectories, moving the toolholder in a situation of virtual reality. Angular values expressed by high precision encoders on the five joints of the toolholder modify "on line" the representation of the configuration of the toolholder within the three dimensional representation of the patient's anatomy.

Artificial Intelligence↗
PubMed1994

Intelligence outcome in children with shunted hydrocephalus of different etiology.

Children with shunted hydrocephalus of differing etiologies were assessed. There was a more selective loss of non-verbal than of verbal intelligence. The verbal and visuo-perceptual abilities were affected by different sets of variables. Variables related to the hydrocephalus had no effects, while associated supratentorial malformations significantly affected non-verbal functions.

Adolescent↗
PubMed1994

Reliability of EEG in the diagnosis of Creutzfeldt-Jakob disease.

Although EEG is generally considered a useful tool for the diagnosis of Creutzfeldt-Jakob disease (CJD), some cases have been reported where the EEG was non-specific. We reviewed a series of 15 CJD patients, observed in our institute in the period 1975-91. In 12 cases the diagnosis was confirmed on post-mortem examination. The prominent aspect of the present series was the homogeneity of clinical, neurophysiological and neuropathological data. All patients showed the presence of periodic sharp wave complexes (PSWC) and EEG reactivity to external stimuli or drugs was uniform. The EEG can give essential information for the diagnosis of CJD if 2 basic conditions are satisfied: (1) serial recordings are performed in relation to the different stages of the disease, and (2) not only the presence of PSWC is considered, but also the reactivity of EEG to dynamic events such as the response to external stimuli and drugs, and the level of consciousness.

Adult↗
PubMed1994

Intraoperative fusion of field images with CT/MRI data by means of a stereotactic mechanical arm.

In this paper we describe a neurosurgical articulated arm used as a pointer and as a support for intraoperative image acquisition, integrated with a graphic 3-D rendering system. The patient's anatomy is volumetrically displayed, from stereotactically acquired CT, MRI, and DSA images; the head holder is the common reference system for image reconstruction and for the calibration of the surgical arm. Arm orientation in stereotatic space is displayed, together with the surgical arm. Arm orientation in stereotatic space is displayed, together with the volumetric reconstruction of cerebral lesions and surrounding healthy tissue. The arm, equipped with fail-safe electromagnetic brakes, can be employed to support imaging sources such as an endoscope, an echographic probe, or a CCD camera, whose images can be stereotactically integrated with preoperative data in performing minimally invasive neurosurgical procedures.

Computer Graphics↗
PubMed1994

Selective inhibition of virus protein synthesis by prostaglandin A1: a translational block associated with HSP70 synthesis.

Cyclopentenone prostaglandins are potent inhibitors of virus replication. The antiviral activity has been associated with the induction of 70-kDa heat shock protein (HSP70) synthesis. In this report, we describe that in African green monkey kidney cells infected with Sendai virus (SV) and treated with prostaglandin A1 (PGA1), SV protein synthesis was selectively blocked as long as HSP70 was being synthesized by the host cell. The block appeared to be at the translational level, as indicated by the following (i) PGA1 had no effect on SV primary transcription, and a dramatic decrease in the abundance of SV mRNA occurred only at later stages of infection; and (ii) treatment with PGA1 started at 6 h postinfection, at which time SV mRNA had already accumulated in infected cells, did not suppress the levels of NP mRNA, but it reduced the amount of ribosome-bound NP mRNA and caused a dramatic decrease in the level of genomic RNA. The PGA1-induced block of SV protein synthesis appeared to be cell mediated, since it was prevented by actinomycin D, while PGA1 had no effect on SV mRNA translation in vitro. The possibility that HSP70 could be a mediator of the antiviral effect is suggested by the fact that treatment with other classical inducers of HSP70, including sodium arsenite, cadmium, and heat shock at 42 degrees C for 5 h, also selectively prevented SV protein synthesis as long as heat shock protein synthesis occurred. Moreover, SV protein synthesis was not inhibited by PGA1 in murine Friend erythroleukemic cells, which lack the ability to induce HSP70 expression in response to PGA1.

Animals↗
PubMed1994

Role of stereotactic biopsy in multifocal brain lesions: considerations on 100 consecutive cases.

One hundred patients affected by multifocal brain lesions were investigated by serial stereotactic biopsy. Systemic diseases and primary neoplasms elsewhere were previously ruled out. The histological diagnosis obtained in this series comprises malignant gliomas in 37% of patients; primary non-Hodgkin's brain lymphoma in 15%; metastatic brain tumours in 15% (no evidence of the primary tumour at the time of stereotactic surgery); low grade gliomas in 12%; infective diseases in 10% (including brain abscesses and multifocal viral encephalitis); and ischaemic lesions in 6%. In addition, two patients with germinomas, two with primitive neuroepithelial tumours, two with multiple telangiectases, and one with a teratoma were also included in this series. Histological findings obtained by stereotactic procedures guided the choice of treatment, avoiding the risks of blind treatments. Indications and future perspectives for stereotactic surgery in multifocal brain lesions are discussed with emphasis on advances in diagnostic and therapeutic tools.

Adolescent↗
PubMed1994

Imaging techniques and computers.

Imaging technology has been the pacesetter of stereotactic technique since its introduction in clinical practice. Quite recently, the extraordinary quality of diagnostic neuroimages and the growing availability of computing power has widened the field of applications of stereotaxy suggesting, at the same time, substantial evolution of its instrumentation. Fusion of multimodal digital images, integration of morphological and functional data, and dimensional rendering techniques have become powerful 'navigational aids' for tissue sampling, functional procedures and image-guided endoscopic surgery. Radiosurgical dose planning systems integrated with image processing and computer graphics routines allow efficient interactive evaluation of tissue-dose volumes superimposition in brachytherapy and external beam focused irradiation. Volumetric guided open surgery, assisted by intraoperative acquisition of stereotactic echographic and microscopic images, allows satisfactory treatment of deep-seated cerebral lesions. Further improvement is to be expected with the implementation of the ongoing development of localizing solutions totally integrated with the microsurgical instrumentation.

Brain↗
PubMed1994

Post-anoxic theta and alpha pattern coma.

Theta pattern coma is a rare EEG finding, described in the course of post-anoxic or post-traumatic coma and interpreted as a "malignant" variant of alpha pattern coma. A case of isolated theta pattern coma, followed by alpha pattern coma is reported. Short temporal succession of such patterns would seem to confirm the hypothesis of a close relationship between them. Possible physiological mechanisms involved in the generation of the patterns are discussed.

Alpha Rhythm↗
PubMed1994

Stereotactically guided transfrontal removal of intraventricular midline tumors in children. Neurosurgical and neuropsychological considerations.

Five children with supratentorial intraventricular midline cerebral tumors were operated on using a stereotactically guided transfrontal approach. Assisted by a three-dimensional graphic reconstruction of cerebral anatomy, the surgeon was able to reach and remove the lesion with minimal damage to healthy parenchyma. Neurosurgical and neuropsychological evaluation of the results suggests that this surgical approach is a valid alternative to the transcallosal route. This image-based intraoperative guidance is as effective as landmark-oriented surgery, which requires section of the corpus callosum, possibly leading to neuropsychological deficits, particularly in the pediatric age group.

Adolescent↗
PubMed1993

A computer controlled stereotactic arm: virtual reality in neurosurgical procedures.

A computer controlled mechanical arm for stereotaxy is presented. It has 5 free joints and can be attached to a stereotactic frame. High precision digital encoders register the angular position of each joint and the computer determines the position of the tip of the instrument in the stereotactic space. Accuracy and usefulness are discussed.

Brain↗
PubMed1993

Trigeminal neuralgia: new surgical strategies.

Presentation of the results of treatment in trigeminal neuralgia, using percutaneous radiofrequency coagulation in 712 cases, percutaneous microcompression in 206 cases, and microvascular decompression in 22 cases. Based on the results the following management strategy is proposed: pts. 65 years or younger = percutaneous balloon compression or, if neuroradiological evidence of neurovascular compression) is given, microvascular decompression. Pts. elder than 65 years = thermorhizotomy. It may be repeated in case of recurrence. If the initial operation was percutaneous compression, the second one should be microvascular decompression or, depending on age or other clinical circumstances of the patient, thermorhizotomy.

Adult↗
PubMed1993

Epidural stimulation for peripheral vascular disease: 10 years experience.

105 patients suffering from arteriosclerotic peripheral vascular disease (PVD) underwent epidural spinal stimulation in the last 10 years. Before 1986 the main indication was ischemic pain without any consideration of trophic lesions (19 pts) while afterward the selection of the patients was more accurate in terms of disease's stage. The analysis of the data shows a more favourable results in the second group. Our experience suggest to use this technique in the treatment of patients in Fontaine's stage III and IV without necrosis and large trophic lesions.

Arteriosclerosis↗
PubMed1993

Toscana virus genomic L segment: molecular cloning, coding strategy and amino acid sequence in comparison with other negative strand RNA viruses.

The complete nucleotide sequence of Toscana (TOS) virus (Bunyaviridae, Phlebovirus) L segment was determined. The L segment is 6404 nucleotides long, containing a single open reading frame (ORF) in the viral complementary sense coding for a protein of 2095 amino acids that, as in the case of negative strand RNA viruses, could be part of the RNA polymerase of TOS virus. This ORF is expressed by a messenger RNA (mRNA) as long as the genomic segment. Like the mRNAs expressed by the genomic segments of the other Bunyaviruses, the L mRNA has non-templated sequences at the 5' end. The comparison of TOS L protein sequence with the corresponding sequences of other negative strand RNA viruses showed a very high homology only with the Rift Valley Fever (RVF) virus. The residues conserved between the two proteins are mainly concentrated in the central region and contain three DD motifs proposed by Argos (1988) to be functional domains of DNA and RNA polymerases. The complete sequence of the Toscana virus L genomic segment has been deposited in the EMBL library with the accession number X68414.

Amino Acid Sequence↗