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Biomedical subjects

F Pisani

Publications and source records attributed to F Pisani.

At least 19 recordsLinked to original sources
PubMed2003

Lamotrigine and remacemide protect striatal neurons against in vitro ischemia: an electrophysiological study.

In the present study, we investigated the cellular and synaptic mechanisms underlying the neuroprotective action of lamotrigine and remacemide. Both drugs, in fact, have been reported to exert a neuroprotective action in in vivo animal models of ischemia. To address this issue, electrophysiological recordings and cell swelling measurements were performed from striatal neurons in control condition and during combined oxygen and glucose deprivation (in vitro ischemia) in a brain slice preparation. Lamotrigine, remacemide, and the active desglycinyl metabolite of remacemide, D-REMA, induced a concentration-dependent reduction of both repetitive firing discharge and excitatory postsynaptic potentials. However, while remacemide and D-REMA exerted their inhibitory action on glutamatergic transmission by blocking NMDA receptors, lamotrigine exerted a preferential presynaptic action, as indicated by its ability to increase paired-pulse facilitation. Both remacemide and lamotrigine were found to be neuroprotective against the irreversible field potential loss and cell swelling induced by in vitro ischemia, and coadministration of low concentrations of these drugs exerted an additive neuroprotective action. A combined use of lamotrigine and remacemide could be employed in clinical trials to enhance neuroprotection in neurological disorders involving an abnormal striatal glutamatergic transmission.

Acetamides↗
PubMed2003

Can breast-feeding protect against schizophrenia? Case-control Study.

BACKGROUND: Human milk, unlike formula feeds, contains long-chain polyunsatured fatty acids, such as docosahexaenoic acid and arachidonic acid which are essential in the development of the central nervous system. If human milk is the optimal food for brain development, and if schizophrenia is a neurodevelopment disorder, might people who become schizophrenic in adult life be less likely to have been breast-fed? AIMS: To compare the incidence and length of breast-feeding in patients, siblings and normal controls and to examine the relationship between the duration of breast-feeding and age at onset of schizophrenia. METHOD: 113 schizophrenic patients were recruited, as were 140 siblings of the patients and 113 nonschizophrenic controls. The breast-feeding history of the patients, their siblings and controls was obtained through interviews with the mothers of the patients and controls. RESULTS: There were no significant differences between groups in the incidence of breast- feeding. The duration of breast-feeding was positively correlated with the age at onset of illness (r = +0.25, p < 0.02). CONCLUSION: Breast-feeding is no less common in those who develop schizophrenia in later life. However, breast milk might postpone the onset of the illness in schizophrenic patients.

Adult↗
PubMed2002

Inhibition in the propagation of fast electrons in plastic foams by resistive electric fields.

The propagation of relativistic electrons in foam and solid density targets has been studied by means of K-alpha spectroscopy. Experimental results point out the role of self-generated electric fields in propagation and the role of heating of matter induced by the passage of fast electrons. A simple analytical formulation has been given and Spitzer conductivity has been shown to be fairly compatible with experimental results.

Journal Article↗
PubMed2001

Neuroprotective effects of lamotrigine and remacemide on excitotoxicity induced by glutamate agonists in isolated chick retina.

The possible neuroprotective effects of two recently developed antiepileptic compounds, lamotrigine (LTG) and remacemide (REMA), against glutamate agonist-induced excitotoxicity have been investigated in the isolated chick embryo retina model. Retina segments from 15- or 16-day-old embryos were incubated in 1 ml of balanced salt solution, at 25 degrees C for 30 min, in the presence or absence of N-methyl-d-aspartate (NMDA), kainic acid (KA), or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) (10 to 200 microM). LTG, REMA, and the active desglycinyl metabolite of REMA (d-REMA) (10-200 microM) were added separately 5 min before glutamate agonists. Retina damage was assessed after 24 h (i) by measuring LDH activity present in the medium, expressed as percentage of total retina LDH activity, and (ii) by histological analysis of retina specimens through scoring for the presence or absence of edema, necrosis, nuclear pyknosis, and cell layer damage. LTG, REMA, and d-REMA reduced LDH release produced by NMDA 58-70% in a dose-dependent manner, with d-REMA being the most potent (EC(50): d-REMA, 25.75 +/- 3.27 microM; REMA, 64.75 +/- 7.75 microM; LTG, 60.50 +/- 6.80 microM; P < 0.001). The drugs had less effect on the LDH release produced by AMPA and KA. Histological analysis confirmed these biochemical results, with all three compounds reducing edema and the number of necrotic and pyknotic nuclei in the ganglion layer. d-REMA provided almost complete protection of the ganglion cell layer against damage produced by NMDA. Combinations of d-REMA and LTG showed additive rather than potentiative effects against NMDA-induced cell injury. The present data provide pharmacological evidence that LTG, REMA, and d-REMA decrease glutamate agonist-induced excitotoxicity in isolated chick retina, findings that might have therapeutic implications for various neurological disorders.

Acetamides↗
PubMed2001

Prevalence, incidence and correlates of HHV-8/KSHV infection and Kaposi's sarcoma in renal and liver transplant recipients.

BACKGROUND: To determine whether the incidence of HHV-8/KSHV infection and the risk of developing KS among organ transplant recipients differ by type of organ transplanted, we calculated the rate of HHV-8/KSHV seroconversion and the risk of developing KS among renal and liver transplant recipients. METHODS: The study population consisted of renal and liver transplant recipients recruited in two transplant centres in Rome, Italy. Both pre-transplant and post-transplant serum samples were available for all participants. The prevalence of HHV-8/KSHV infection before transplantation was calculated. To determine risk factors for infection, we calculated ORs and 95% CI. Seroconversion rates (i.e. attack rates) after transplantation were also calculated. Differences in attack rates were calculated using a binomial test for proportions. RESULTS: Of the 130 participants, 21 (16.1%) were HHV-8/KSHV-positive before transplantation. Women were more likely to be infected than men, whereas no difference was observed by type of organ transplanted. Of the 109 initially negative individuals, 13 (11.9%) developed anti-HHV-8/KSHV antibodies after transplantation. The incidence of HHV-8/KSHV infection tended to be higher among liver transplant recipients. Four renal transplant recipients and none of the liver transplant recipients developed KS after transplantation. The risk of KS was higher among recipients who were already HHV-8/KSHV-positive before transplantation. CONCLUSIONS: HHV-8/KSHV seroconversion rates appear to be higher among liver transplant recipients, compared to renal transplant recipients. However, renal transplant recipients tend to have a higher risk of KS. HHV-8/KSHV reactivation appears to play a greater role on the risk of KS than incident infections.

Adolescent↗
PubMed2000

Posttransplant donor-specific antibody characterization and kidney graft survival.

This study was designed to investigate the clinical relevance of donor-specific antibodies (DS-Abs) and their influence on graft survival. Among 106 patients who underwent cadaveric kidney donor transplantation and were monitored by flow cytometry crossmatch (FCXM) during the 1st posttransplantation year, 25 (23.6%) resulted positive for DS-Ab production. During a 2-year follow up only 12 of the 81 FCXM-negative patients (14.8%) suffered rejection vs 17 of 25 FCXM-positive patients (68%; P = 0.00001). Correlating graft loss to DS-Ab production, 9 FCXM-positive patients lost the graft vs only 1 among the FCXM-negative patients. A worse graft function was evidenced in FCXM-positive subjects who had also suffered rejection episodes than in those which had acute rejection but did not produce DS-Abs. A high incidence of HLA-AB mismatches was found in FCXM-positive subjects which produced anti-class I antibodies. FCXM appears useful in estimating posttransplant alloimmune response. Moreover our findings confirm the harmful effects of anti-class I DS-Abs on long-term graft survival.

Antibody Formation↗
PubMed2000

Explanations for the observed increase in fast electron penetration in laser shock compressed materials

We analyze recent experimental results on the increase of fast electron penetration in shock compressed plastic [Phys. Rev. Lett. 81, 1003 (1998)]. It is explained by a combination of stopping power and electric field effects, which appear to be important even at laser intensities as low as 10(16) W cm-2. An important conclusion is that fast electron induced heating must be taken into account, changing the properties of the material in which the fast electrons propagate. In insulators this leads to a rapid insulator to conductor phase transition.

Journal Article↗
PubMed2000

Experimental evidence of electric inhibition in fast electron penetration and of electric-field-limited fast electron transport in dense matter

Fast electron generation and propagation were studied in the interaction of a green laser with solids. The experiment, carried out with the LULI TW laser (350 fs, 15 J), used K(alpha) emission from buried fluorescent layers to measure electron transport. Results for conductors (Al) and insulators (plastic) are compared with simulations: in plastic, inhibition in the propagation of fast electrons is observed, due to electric fields which become the dominant factor in electron transport.

Journal Article↗
PubMed2000

Neurofibromatosis type 1 and precocious puberty.

Since neurofibromatosis type 1 (NF1) is a well known cause of precocious puberty (PP), we reviewed 412 NF1 pediatric patients to evaluate the prevalence of PP, the association with optic pathway tumors (OPT), and other clinical, auxological and hormonal data. Thirty-one of 412 patients had OPT (7.5%), 10/412 PP (2.4%), and in seven of these PP was associated with OPT (7/31, 22.6%). OPT in patients with PP involved the chiasm in four patients, and the optic nerves alone in three patients. The age at the onset of puberty (or better at diagnosis) ranged from 5.2 to 7.5 yr in girls (n=6) and from 7.9 to 8.9 yr in boys (n=4). LHRH agonist therapy was used in only three children because in the others the predicted height at diagnosis was good, treatment was refused or the patients were referred to us too late. The three treated patients attained a final height within the familial range. In the untreated patients the progression of puberty was not too rapid and final height was slightly below the genetic target in four patients; however, three patients had a final height markedly below the familial range. In conclusion, the prevalence of PP is increased in children with NF1, and frequently but not exclusively is associated with OPT. Moreover, sexual precocity does not seem to be necessarily bound to chiasmatic OPT. Treatment seems to be useful in the children with younger age at the onset of puberty or with a progressive decline in predicted final height.

Adolescent↗
PubMed2000

[Clinical features in subjects with congenital anomalies of the corpus callosum].

The corpus callosum is a connecting structure between the two cerebral hemispheres. Its development occurs between 8th and 20th week of gestation. Anomalies of the corpus callosum are divided into malformative or acquired anomalies and may be isolated or associated with other cerebral malformations. The diagnosis of an alteration of the corpus callosum is fundamentally based on neuroradiological examinations. In our study we evaluate the major clinical findings, the psychomotor development, the electroencephalographic and neuroradiological features in a group of 14 children with congenital callosal anomalies, trying to single out how the associated cerebral malformations interfered with the clinical manifestations and especially the prognosis. It was not possible to highlight a distinctive symptom indicative of the presence of a corpus callosum anomaly; nevertheless in 11/14 children there was a psychomotor delay of varying degree. 42% of our subjects presented epilepsy, with a typical West syndrome in 5/6. Children affected by isolated callosum anomalies did not present any significant clinical manifestations. Finally, we conclude that the determinating factors in the severity of the clinical-electroencephalographic picture as a whole, and especially in the prognosis of our patients are the cerebral malformations associated to the callosum anomalies.

Agenesis of Corpus Callosum↗
PubMed2000

[Retinopathy of prematurity: incidence and risk factors].

The study analyses the incidence of the retinopathy of prematurity (ROP) and its correlation with the most important risk factors in neonates with gestational age (GE) < or = 32 weeks and/or with birth weight (BW) < or = 1500 g. The cohort of our study is composed by 305 preterms with Mean GE of 29.8 weeks and Mean BW of 1312 g, studied at the Neonatal Intensive Care Unit of the University of Parma during January 1993-December 1999. The incidence of ROP resulted 19.7% in our group and was inversely proportional to the GE and BW. No preterms with GE < or = 32 weeks presented retinopathy, while there has been an incidence of the 65% in the subjects with GE lower than 26 weeks. The most severe grade of ROP was mainly seen in the newborns with the lowest GE (31%), whilst only the 1.5% of the preterms with GE of 30-31 weeks developed ROP of stage 3 or 3+. Similar results were seen when the data were compared with the birth weight. However a direct relation was seen with the duration of the O2 therapy and with the typical pathologies of the prematurity, namely respiratory distress syndrome (RDS) and intraventricular haemorrhages (IVH). Among the other risk factors evaluated, the blood transfusion was the most relevant.

Humans↗
PubMed1999

A pilot study on the safety and effectiveness of immunosuppression without prednisone after liver transplantation.

BACKGROUND: Corticosteroids are commonly used in the immunosuppression therapy after liver transplantation, yet are associated with considerable side effects. Retrospective studies have shown that corticosteroids can be safely withdrawn from months to years after transplant. We prospectively investigated the effects of early immunosuppression without the use of corticosteroids on graft outcome and transplant complications. METHODS: Forty-five patients undergoing liver transplantation were randomized to receive immunosuppression composed of cyclosporine microemulsion and azathioprine with (n=22) or without prednisone (n=23), in conventional doses. In those patients who received prednisone, this was withdrawn within 3 months after transplant. The median follow-up of survivors was 14 months (range: 6-24). The study end points were to determine graft survival and function, infectious complications, including hepatitis C virus (HCV)-RNA levels in HCV-infected recipients, acute rejection, kidney function, and metabolic complications. RESULTS: Eleven deaths occurred, 6 of which were in the prednisone group. Two-year survival did not differ between patients treated with or without prednisone (70.2% vs. 78.3%, P=0.83), nor did the causes of death. No differences were observed with regard to graft function, renal function, and infectious complications. In the subset of patients who received transplants for HCV-related cirrhosis, the dynamics of virus replication HCV-RNA was faster among those treated with prednisone. The incidence and severity of acute rejection was similar in the two groups. More than 80% of acute rejections in both groups were classified as mild or moderate and underwent spontaneous resolution. Only two patients in each group had severe acute rejection requiring additional treatment with high-dose steroids. Patients receiving prednisone tended to have greater biochemical signs of cholestasis, higher serum cholesterol and glucose levels, and more frequent insulin requirement than those treated without corticosteroids. CONCLUSIONS: Liver transplantation can be performed safely without using corticosteroids in the early postoperative course, and there is no need for routine aggressive steroid treatment of established acute rejections.

Adult↗
PubMed1999

Autism in tuberous sclerosis: evoked potential evidence for a deficit in auditory sensory processing.

OBJECTIVE: Autism is a frequent manifestation of tuberous sclerosis complex (TSC) being reported in up to 60% of the patients. Its presence is in association with cortical and subcortical lesions involving the temporal lobes. This study was designed to shed light on the functional mechanisms linking anatomical lesions of TSC and behavioural phenotype by investigating scalp recorded event related potentials to auditory stimuli. METHODS: Fourteen children with TSC, seven of which fulfilled the DSM IV criteria for autistic disorder were selected for this study. All of the subjects underwent high resolution MRI, EEG, brainstem auditory evoked potentials, cognitive and behavioural evaluation. Electrical evoked responses to two different pitches, presented with different probability (80% 1000 Hz, 20% 1500 Hz) were recorded from 21 scalp electrodes in the autistic and non-autistic subgroups, to assess central auditory processing and automatic memory. RESULTS: The first component of the long latency auditory response (N1) had a significantly prolonged latency with lower amplitude in all of the patients with autistic behaviour who, contrary to non-autistics had MRI lesions involving one or both temporal lobes. A mismatch negativity was detected in all subjects and had a longer latency in subjects with autistic behaviour. CONCLUSIONS: To our knowledge this is the first electrophysiological evidence of a deficit in auditory information processing and automatic memory in TSC patients with autistic behaviour.

Auditory Perception↗