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Biomedical subjects

R Coppola

Publications and source records attributed to R Coppola.

At least 127 records · Page 7Linked to original sources
PubMed1991

Occipital lobe morphology in normal individuals assessed by magnetic resonance imaging (MRI).

The topography of visual evoked potentials (VEP) is dependent on occipital lobe morphology. Using magnetic resonance imaging we examine the sulcal pattern (the calcarine and parieto-occipital sulci), and assess the size of the cuneus and the asymmetry of the occipital lobes, computed separately for its ventral and dorsal segments. No differences were found for either the cuneus or the sulci pattern. In contrast, hemispheric asymmetry values appeared to be substantial. The predominance of the left occipital area was seen distinctly in the ventro-caudal portion of the occipital lobe. It was frequently reversed in the dorsal aspect of the lobe, notably in more rostral cuts. Such complexities may lead to ambiguities in interpreting VEP asymmetries.

Adolescent↗
PubMed1991

IMA-graft patency control by thermal coronary angiography during coronary bypass surgery.

Thermal coronary angiography (TCA) was evaluated for the intraoperative assessment of graft patency and flow in internal mammary artery (IMA) bypass grafts. TCA was performed in 210 patients undergoing 460 vein and 153 IMA bypass grafts after completion of the distal anastomoses. The IMA grafts and the recipient coronary arteries were delineated by the temperature differential between a cold epimyocardium and the perfusing warm blood after bulldog clamp release. TCA provided information about graft and anastomosis patency, initial flow patterns, and native coronary stenoses. TCA was performed in all studied IMA bypass grafts: 142 grafts were patent. Low flow but patency was observed in 24 IMA grafts and 11 IMA grafts showed no flow. Subsequently, 8 anastomotic failures and 3 proximal IMA graft occlusions were encountered. Based on these findings, 8 anastomoses were successfully revised and 7 additional vein grafts were added. One low flow IMA graft was not revised leading to postoperative ST elevation. Thirty-one distal native coronary stenoses were detected in the recipient LADs, 3 of which were not seen in the preoperative cineangiogram. In 20 instances, TCAs were obscured by an excess of fat or myocardium impeding image analysis. In 8 cases, TCA results were confirmed by conventional angiography postoperatively showing an excellent correlation in all cases. We conclude that intraoperative TCA demonstrates early IMA graft function and initial flow patterns. During our study, TCA documented a 7.2% IMA graft early failure rate. Intraoperative decision making was aided by TCA in 9.2% of all IMA grafts; this confirmed the clinical relevance of TCA.

Adult↗
PubMed1991

Hepatitis-C virus infection in Italy: a multicentric sero-epidemiological study (a report from the HCV study group of the Italian Association for the Study of the Liver).

To assess possible geographical differences in the spread of hepatitis-C virus (HCV), the prevalence of antibodies against HCV (anti-C-100-3) was investigated in various adult population groups in 29 centres in Italy. Anti-HCV was positive in 375 out of 28,433 voluntary blood donors (1.3%): prevalence was higher in southern Italy (1.51%) than in the northern regions (1.28%), but the difference was not statistically significant. Anti-HCV prevalence was similar in the north and south in post-transfusion chronic hepatitis (91%), haemophiliacs (73%), intravenous drug users (70%), and haemodialysis patients (28%), where parenteral contacts are obvious, and in HBsAg carriers (14%), a group with evidence of previous parenteral contamination. In contrast, anti-HCV prevalences were found to be significantly higher in the south than in the north and central Italy among patients with hepatocellular carcinoma (HCC) (73 vs 59%), cryptogenic liver disease (67 vs 58%), autoimmune chronic hepatitis (72 vs 44%) and alcoholic liver disease (51 vs 34%). These results indicate a very high circulation of HCV in Italy, with maximum incidence in the south and in the islands. They suggest that its spread in the community can occur through inapparent parenteral routes as observed for hepatitis-B (HBV) and hepatitis-delta viruses (HDV) and possibly facilitated by poorer social-demographic and life-style factors.

Adult↗
PubMed1991

[Hemodynamic characteristics of heart transplant patients in the early postoperative period].

In spite of good long-term results, heart transplantation continues to carry a significant risk of hospital mortality (about 10%). Among cardiac deaths, right-heart failure due to an elevated pulmonary vascular resistance represents a main contributing factor. Since no quantitative data on the hemodynamic situation early after transplantation are available, we monitored 27 heart transplant patients during the first four postoperative days. Data derived from right-heart catheterization, dosages of catecholamines and vasodilative substances were measured at 2, 4, 16, 24, 48, 72, and 96 h after the operation. Oxygen consumption and serum lactate levels were determined until 48 h postoperatively. During that time cardiac output remained constant (2 h: 6.6 +/- 1.4 l/min). The dosage of catecholamines was highest immediately after transplantation (2 h: 0.229 +/- 0.136 micrograms adrenaline/kg/min) and could be reduced thereafter. Highest values of pulmonary vascular resistance were obtained 2 h postoperatively (160 +/- 48 dyn.s.cm-5). This early postoperative situation may result in the development of right-heart failure as observed in two patients who died despite the use of prostacycline on the third and eighth postoperative days. To counteract the systemic vasodilative side-effects of prostaglandins, temporary atrial pacing seems to be useful. In our study atrial stimulation led to an increase of cardiac output and a moderate elevation of mean arterial blood pressure. Only a poor correlation between pre- and postoperative (2-h) pulmonary vascular resistance data could be observed. In most patients the pulmonary vascular resistance decreased during the postoperative course. This was not the case in patients with fixed pulmonary hypertension. We, therefore, conclude that preoperative diagnostics should be refined to recognize patients at risk in order to reduce postoperative mortality.

Adult↗
PubMed1991

The effect of amphetamine on regional cerebral blood flow during cognitive activation in schizophrenia.

To explore the role of monoamines on cerebral function during specific prefrontal cognitive activation, we conducted a double-blind placebo-controlled crossover study of the effects of 0.25 mg/kg oral dextroamphetamine on regional cerebral blood flow (rCBF) as determined by 133Xe dynamic single-photon emission-computed tomography (SPECT) during performance of the Wisconsin Card Sorting Test (WCST) and a sensorimotor control task. Ten patients with chronic schizophrenia who had been stabilized for at least 6 weeks on 0.4 mg/kg haloperidol participated. Amphetamine produced a modest, nonsignificant, task-independent, global reduction in rCBF. However, the effect of amphetamine on task-dependent activation of rCBF (i.e., WCST minus control task) was striking. Whereas on placebo no significant activation of rCBF was seen during the WCST compared with the control task, on amphetamine significant activation of the left dorsolateral prefrontal cortex (DLPFC) occurred (p = 0.0006). Both the mean number of correct responses and the mean conceptual level increased (p less than 0.05) with amphetamine relative to placebo. In addition, with amphetamine, but not with placebo, a significant correlation (p = -0.71; p less than 0.05) emerged between activation of DLPFC rCBF and performance of the WCST task. These findings are consistent with animal models in which mesocortical catecholaminergic activity modulates and enhances the signal-to-noise ratio of evoked cortical activity.

Adult↗
PubMed1990

Adequacy of the International 10-20 electrode system for computed neurophysiologic topography.

The adequacy of the International 10-20 System is reviewed in light of demands imposed on the accuracy of lead placement by improvements in spatiotemporal brain electrical activity mapping technology. Computed tomography (CT) and magnetic resonance imaging (MRI) studies reveal that the most frequent sources of inaccuracy of electrode locations are difficulties in defining the inion, variance in the anatomy of the occipital bone, inconspicuous sagittal deformities, variance of sulcal pattern, and brain width asymmetries. Owing to these factors, electrodes placed bilaterally and equidistant from the nasion-inion line may not be homotopically located. Therefore, the authors suggest that practitioners who employ the 10-20 System in order to gain precise and more individualized laterality information do so with extreme caution until the range of placement and interpretative errors is more precisely determined using CT/MRI-assisted EEG.

Brain↗
PubMed1990

[Surgical treatment of Wolff-Parkinson-White syndrome--experiences with 87 surgically treated patients].

Since January 1984, 87 patients (pts) (57 male, 30 female; age 3 to 64 years) with Wolff-Parkinson-White syndrome were operated upon. The indication for surgical treatment was documented recurrent, paroxysmal tachycardia refractory to medical treatment in 85 cases. Eleven pts (13%) had additional heart disease. 87 pts had a total of 103 accessory pathways (AP). AP was localized at the left free wall in 68% (70 AP), at the right free wall in 16% (16 AP), and localized septally in 17% (17 AP). Thirteen pts (15%) had multiple AP (10 pts had two and three pts had three AP). 87 AP were known preoperatively, 96 were localized intraoperatively, and seven were diagnosed during reoperation. Twenty-seven pts were left lateral AP were operated by the epicardial approach and 37 pts by the endocardial approach. Patients with right lateral AP were approached by an epicardial technique in six cases, and by a transmural technique in five. Cryotechnique was applied additionally in 85 pts. Twelve pts suffered recurrences, 11 were reoperated. 101 AP (98%) were dissected successfully, of which 13 (13%) were ablated during reoperation. All pts survived the initial operation. Two pts died after reoperation. One pt is pacemaker-dependent due to a persisting postoperative AV block. We conclude that surgical dissection of accessory pathways can now be offered as an alternative to the non-surgical treatment modes, with low risk and yielding a high success rate.

Adolescent↗
PubMed1989

Monoclonal antibodies directed to the calcium-free conformation of human protein S.

Four mouse hybridomas secreting monoclonal antibodies specific for human protein S (PS) have been generated. The antibodies, all of the IgG1 subclass, were designated S2, S3, S8, and S10. In a fluid phase radioimmunoassay, the binding of monoclonal antibodies to PS was about 30% greater in the presence of EDTA and totally inhibited in presence of Ca2+. Using the same technique, we performed displacement curves of 125I-labeled PS by purified PS, thrombin-cleaved PS, normal plasma, plasma from a patient on warfarin therapy, and plasma from a patient with no free PS and only PS bound to C4b-binding protein. The slopes of the curves show that the monoclonal antibodies reacted equally with all the tested forms of PS indicating that the antigenic site(s) to which the monoclonal antibodies are directed are present and exposed in free and bound PS, in thrombin-cleaved PS, and in the coumarin form of the protein. Each EDTA-dependent antibody, immobilized on Sepharose 4B-CNBr was used to purify PS from the barium citrate-absorbed, ammonium sulphate-soluble fraction of plasma. The fraction eluted from the immunoabsorbent with a buffer containing 4 mmol/l CaCl2 and analysed by SDS-PAGE, contained two bands, one migrating with conventionally purified PS and the other with purified C4b-binding protein. Homogeneous PS was obtained by chromatography of the barium citrate adsorbate on a DEAE-Sephadex column. The protein peak containing the bulk of PS was subsequently applied to the immunoadsorbent and eluted with 4 mmol/l CaCl2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

EEG asymmetries may be affected by cranial and brain parenchymal asymmetries.

The plagiocephaly index, an index that reflects an underlying anatomic asymmetry of the brain, was assessed in ten schizophrenic patients and its values were correlated with the lateral distribution of quantitatively evaluated EEG. The correlations between the index and alpha power at F7 were significant, positive for frontal asymmetry (frontal bulging) and negative for occipital flattening. We then studied ten normal subjects in an attempt to illuminate the contribution of several cephalic and cranial variables to the imbalance of alpha-afterdischarges (AD) of VEP recorded at O1-O2. The asymmetry index of AD was computed and correlated with asymmetries of CT-derived measures of occipital bone thickness, occipital lobe width, mastoid area, and sulcal asymmetry (the asymmetry of intraparietal sulcus location from the longitudinal fissure). With the exception of the sulcal variable all measures significantly covaried with alpha AD. These findings caution that it may be important to determine cranial and brain parenchymal asymmetries where brain laterality is pertinent to studies of EEG.

Adolescent↗
PubMed1989

Value of ERCP in the diagnosis and management of pre- and postoperative biliary complications in hydatid disease of the liver.

Twenty-nine patients with symptomatic hydatid disease of the liver were evaluated preoperatively by endoscopic retrograde cholangiopancreatography (ERCP) in the years 1982-1987. In the same period, 6 patients who previously underwent surgery for the parasitic disease also underwent ERCP because of postoperative symptoms of biliary obstruction. Findings at ERCP excluded biliary tract involvement in 11 cases. Positive findings were shown in 24 patients, including compression of the bile ducts in 4, small cysto-biliary communications in 5, intrabiliary rupture in 9, residual hydatid material in the common bile duct, and sclerosing cholangitis in 3. Endoscopic removal of migrated hydatid debris was achieved in 8 patients, avoiding reoperation in 4.

Adult↗
PubMed1989

EEG spectra in severely dyslexic men: rest and word and design recognition.

To identify and localize differences in brain functioning, electrical activity was recorded with a full complement of scalp electrodes in 14 healthy, severely dyslexic men (mean age = 22 years, S.D. = 3) and 15 matched controls during rest and during word and design recognition. The electroencephalograms were spectrum analyzed, and the mean amplitude in each of 5 bands--delta, theta, alpha, slow beta and fast beta--compared topographically between conditions and groups. The two tasks did not elicit differentially lateralized patterns of electrical activity, but produced anteroposterior differences in alpha and theta. The Designs task, more difficult for both groups, was associated with less posterior alpha than was the Words task. The strongest group difference was likewise seen along an anteroposterior axis on the Designs task. With performance equal to that of controls, the dyslexics showed relatively greater fronto-central theta and less posterior theta (a more activated state), suggesting that dyslexics were compensating for less efficient information processing. There were no group differences in overall amplitude in any band for any condition. The differences in the topographic distribution of theta may reflect subtle differences in brain organization or compensatory recruitment of widely distributed neuronal networks.

Adult↗