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Biomedical subjects

G Capocchi

Publications and source records attributed to G Capocchi.

18 recordsLinked to original sources

Early admission to stroke unit influences clinical outcome.

An improvement in patient arrival time to stroke unit (SU) is recommended, since earlier stroke management seems to improve 'per se' functional outcome. The objective of this study was to determine if early admission influences the outcome, reduces disability and mortality at discharge and three months later independent of tlirombolytic treatment. Consecutive acute stroke patients admitted to SU between January 1st 2000 and December 31st 2003 were studied in order to analyze the actual role of acute management independent specific pharmacological treatment, we excluded subjects who underwent rt-PA. 35.8% of 2,041 consecutive stroke patients arrived within 3 hours; 62.4% within 6 hours; 37.6% arrived later. Approximately 80% of the <6 hour patients presented a National Institutes of Health Stroke Scale (NIHSS) >4 and modified Rankin Scale (mRS) score >2 in comparison with 60% of the >6 hour patients. In hospital (8.7%) and three-month (7.3%) mortality in <3 hour patients were not significantly different from what observed in >3 hour patients (6.8% and 6.1% respectively) while functional outcome after three months was better in <3 hour patients (NIHSS: 34.6 vs 15.2; mRS: 32.9% vs 16.8%). Old age, history of TIA, cardioembolic etiology, severity of neurological deficit and hemorrhagic stroke type all led to earlier arrival time. Admission within 3 hours 'per se' improves outcome and reduced disability at three months.

Adult↗

Glial cell line-derived neurotrophic factor and somatostatin levels in cerebrospinal fluid of patients affected by chronic migraine and fibromyalgia.

The aim of the present study was to verify cerebrospinal fluid (CSF) levels of glial cell line-derived neurotrophic factor (GDNF) and somatostatin, both measured by sensitive immunoassay, in: 16 chronic migraine (CM) patients, 15 patients with an antecedent history of migraine without aura diagnosed as having probable chronic migraine (PCM) and probable analgesic-abuse headache (PAAH), 20 patients affected by primary fibromyalgia syndrome (PFMS), and 20 control subjects. Significantly lower levels of GDNF and somatostatin were found in the CSF of both CM and PCM + PAAH patients compared with controls (GDNF =P < 0.001, P < 0.002; somatostatin = P < 0.002, P < 0.0003), without significant difference between the two groups. PFMS patients, with and without analgesic abuse, also had significantly lower levels of both somatostatin and GDNF (P < 0.0002, P < 0.001), which did not differ from those of CM and PCM + PAAH patients. A significant positive correlation emerged between CSF values of GDNF and those of somatostatin in CM (r = 0.70, P < 0.02), PCM + PAAH (r = 0.78, P < 0.004), and PFMS patients (r = 0.68, P < 0.008). Based on experimental findings, it can be postulated that reduced CSF levels of GDNF and somatostatin in both CM and PCM + PAAH patients can contribute to sustained central sensitization underlying chronic head pain. The abuse of simple or combination analgesics does not seem to influence the biochemical changes investigated, which appear to be more strictly related to the chronic pain state, as demonstrated also for fibromyalgia.

Adult↗

Balance disorders in headache patients: evaluation by computerized static stabilometry.

OBJECTIVES: The aim of the study was to investigate the occurrence of equilibrium disturbances in headache patients, during the interictal period, by computerized static stabilometry. MATERIALS AND METHODS: Sixty-seven patients were studied: 35 with migraine without aura (MwoA), 12 with tension-type headache (TTH) in the episodic form (ETTH) + MwoA, and 20 with only TTH [10 ETTH + 10 chronic (CTTH)]. The stabilometric parameters considered were: statokinesigram length (L) and surface (S) in open (EO) and closed (EC) eyes conditions with/without occlusal bite, EC with head retroflexion (ECR), and optokinetic stimulation (OKN). RESULTS: The alteration of at least one of the stabilometric parameters was observed in 45 patients (67.2%): 21 MwoA, 8 ETTH + MwoA, and 16 TTH (8 ETTH + 8 CTTH). CONCLUSION: In TTH patients (ETTH, CTTH, ETTH + MwoA), the stabilometric findings show a proprioceptive alteration induced by cervicofacial muscle contraction, which was peripheral in origin. In MwoA patients the alterations appear under OKN and support a control impairment in involuntary oculomotility of central origin.

Adult↗

Platelet-activating factor (PAF) in internal jugular venous blood of migraine without aura patients assessed during migraine attacks.

The aim of the study was to verify the production of PAF and the activity of PAF acetyl-hydrolase (PAF-AH), the enzyme involved in the catabolism of this phospholipid mediator, in migraine attacks. Their levels were determined during migraine crises in serial samples of internal jugular venous blood taken from five migraine patients without aura, who were admitted to the hospital during the crises. Internal jugular venous blood samples were taken immediately after catheter insertion at 1, 2, and 4 h after attack onset, and within 2 h from its cessation. PAF was purified by high-performance liquid chromatography (HPLC) and determined by radioimmunoassay method. The enzymatic activity of PAF-AH was measured by reverse-phase HPLC, based on the derivatization with 7-diethylaminocoumarin-3-carbonylazide. In the internal jugular venous blood of migraine patients without aura (MO), an increase was observed in PAF levels, which was already evident at the time of catheter insertion (885.6 +/- 82.8) and at the first hour (868.4 +/- 65.24) (ANOVA: P < 0.0001). PAF levels remained elevated through the second (746.8 +/- 82.95), fourth (700.6 +/- 34.93) and sixth hours (644.4 +/- 42.85), and then decreased at the end of the attack, reaching levels significantly lower than those measured at the time of catheter insertion (565.5 +/- 38.34). The activity of PAF-AH showed an opposite trend with higher values at the first hour and significantly lower values at the second and fourth hours from the beginning of the migraine attack (ANOVA: P < 0.02). The increased production of PAF may account for persistent platelet activation during migraine crises, even in the presence of an increased production of nitric oxide (NO) end-products which, on the other hand, should instead intervene in counteracting and limiting platelet activation. Potential sources of PAF production are the endothelial cells from cerebral vessels, stimulated by trigeminal neuropeptides, platelets themselves, and mast cells, as suggested by the neurogenic inflammation model.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

Giant axonal neuropathy with subclinical involvement of the central nervous system: case report.

The case of a 17-year-old girl with slowly progressive sensory-motor neuropathy is described. Sural nerve biopsy showed abnormally enlarged exons filled with neurofilaments. Neurofilament accumulation was limited to the axons and was not found in other cells of the skin or peripheral nerve. The patient showed EEG and brain MRI abnormalities, but there was no clinical evidence of central nervous system involvement. Although these findings suggest an atypical attenuated form of giant axonal neuropathy, a new nosological entity cannot be excluded.

Adolescent↗

Valproate-induced epileptic tonic status.

We observed a young patient with slight mental retardation, suffering from drug-resistant tonic-clonic seizures, who presented a status epilepticus (SE), in two separate periods when valproic acid (VPA) was added to the phenobarbital (PB) already being used in the patient's therapy. The VPA-induced SE was characterized by normal plasma levels of antiepileptic drugs (AEDs), normal ammonemia and normal liver function. The case we studied represents the first report on a VPA-induced SE. Furthermore the case confirms that VPA, as well as causing encephalopathy secondary to hyperammonemia, may also provoke a primary involvement of the central nervous system (CNS), specially when used in young epileptic, mentally retarded subjects. In an attempt to explain the paradoxical effect of VPA we hypothesise that the SE could be due to an increase in excitatory activity producing a consequent epileptogenic effect in those subjects with a predisposition for toxic reaction to VPA therapy due to congenital anomalies of neural networks.

Adolescent↗

The role of GABA in NMDA-dependent long term depression (LTD) of rat medial vestibular nuclei.

The role of GABA in NMDA-dependent long term depression (LTD) in the medial vestibular nuclei (MVN) was studied on rat brainstem slices. High frequency stimulation (HFS) of the primary vestibular afferents induces a long lasting reduction of the polysynaptic (N2) component of the field potentials recorded in the dorsal portion of the MVN. The induction but not the maintenance of this depression was abolished by AP5, a specific blocking agent for glutamate NMDA receptors. The involvement of GABA in mediating the depression was checked by applying the GABAA and GABAB receptor antagonists, bicuculline and saclofen, before and after HFS. Under bicuculline and saclofen perfusion, HFS provoked a slight potentiation of the N2 wave, while the N2 depression clearly emerged after drug wash-out. This indicates that GABA is not involved in inducing the long term effect, but it is necessary for its expression. Similarly, the LTD reversed and a slight potentiation appeared when both drugs were administered after its induction. Most of these effects were due to the bicuculline, suggesting that GABAA receptors contribute to LTD more than GABAB do. According to our results, it is unlikely that the long lasting vestibular depression is the result of a homosynaptic LTD. On the contrary, our findings suggest that the depression is due to an enhancement of the GABA inhibitory effect, caused by an HFS dependent increase in gabaergic interneuron activity, which resets vestibular neuron excitability at a lower level.

2-Amino-5-phosphonovalerate↗

Theta burst stimulation is optimal for induction of LTP at both apical and basal dendritic synapses on hippocampal CA1 neurons.

The efficacy of stimulation patterns consisting of brief high frequency bursts repeated at various intervals to induce long-term potentiation (LTP) at synapses on apical and basal dendrites of CA1 hippocampal neurons was tested in vitro. Both apical and basal dendritic synapses exhibited maximal LTP after bursts repeated at 5-10 Hz, i.e. close to the frequency of the endogenous hippocampal theta rhythm. As at apical dendritic synapses, LTP at basal dendritic synapses was blocked by an antagonist of NMDA receptors. Basal dendritic LTP was significantly greater in magnitude than apical dendritic LTP, although the reason for this is unknown.

2-Amino-5-phosphonovalerate↗

NMDA receptor-mediated long term modulation of electrically evoked field potentials in the rat medial vestibular nuclei.

The effect of high frequency stimulation (HFS) of the primary vestibular afferents on field potentials recorded in the ipsilateral Medial Vestibular Nuclei (MVN) was studied. Our results show that potentiation and depression can be induced in different portions of MVN, which are distinguishable by their anatomical organization. HFS induces potentiation of the monosynaptic component in the ventral portion of the MVN, whereas it provokes depression of the polysynaptic component in the dorsal portion of the same nucleus. The induction of both potentiation and depression was blocked under AP5 perfusion, thus demonstrating that NMDA receptor activation mediates both phenomena. Furthermore, the finding that the field potentials were not modified during perfusion with DL-AP5, as previously reported, supports the hypothesis that NMDA receptors are not involved in the normal synaptic transmission from the primary vestibular afferent fibres, but are only activated following hyperstimulation of this afferent system. Our results suggest that the mechanisms of long term modification of synaptic efficacy observed in MVN may underlie the plasticity phenomena occurring in vestibular nuclei.

2-Amino-5-phosphonovalerate↗

Role of NMDA receptors in the compensation of ocular nystagmus induced by hemilabyrinthectomy in the guinea pig.

The possibility that N-methyl-D-aspartate (NMDA) receptor activation plays a role in inducing the vestibular compensation following hemilabyrinthectomy (HL) in guinea pigs, was verified by means of continuous intraventricular osmotic pumping of DL-2-Amino-5-phosphono-valeric acid (APV). Our results show that high doses (40 and 20 mM) of APV decrease both the combined OKR and VOR and the nystagmus following HL. Low doses of APV (2.5 mM), affect the time course of the ocular compensation by maintaining a higher level of nystagmus beat frequency and by delaying the nystagmus disappearance. On the contrary, the compensation time course is not affected by administering APV later on in the compensation period. Therefore, it appears that NMDA receptors are activated during the precocious phase of vestibular compensation, when a large vestibular imbalance is present. This finding is explained by the development of NMDA receptor hypersensitivity, in the functionally inactivated commissural system or by the occurrence of NMDA-mediated long-term potentiation.

2-Amino-5-phosphonovalerate↗

beta-N-acetylhexosaminidases in human cerebrospinal fluid and serum of patients with multiple sclerosis.

Beta-N-Acetylhexosaminidase activity and isoenzyme have been investigated in normal human cerebrospinal fluid and that of patients with multiple sclerosis. beta-N-acetylhexosaminidase activity in normal cerebrospinal fluids has been resolved into five components. The major component was in a form that eluted from DEAE cellulose at the same salt concentration as hexosaminidase As, the isoenzyme previously identified in human serum. Cerebrospinal fluid from patients exhibited a different isoenzyme profile, showing a remarkable increase in a form having a pI which was more acidic than that of As. These changes have a potential use in the diagnosis and further biochemical characterization of multiple sclerosis.

Chromatography, Ion Exchange↗

Creatine kinase BB activity in serum of patients with acute stroke: correlation with the severity of brain damage.

BB-CK activity was measured in 11 patients with stroke and in 10 controls. Blood samples were taken 36 hours after the clinical stroke onset in every patient. Sera were stored at -80 degrees and analyzed within two months. The creatine kinase isoenzymatic pattern was determined by ion-exchange column separation and gradient elution system. The mean BB-CK concentration in patients with stroke was significantly higher than in controls (p less than 0.01). In the group of "stroke" patients we found a correlation between severity of brain damage, as suggested by the clinical picture and CT scans, and serum values of BB-CK.

Adult↗

Quantitative data on cell loss and cellular atrophy of intralaminar nuclei following cortical and subcortical lesions.

Morphological changes in the intralaminar nuclei centralis medialis, paracentralis and centralis lateralis of the thalamus of adult cats after cortical excisions have been determined by means of a quantitative method. The number and size of the remaining neurons on the operated side have been compared with those of the normal side. The differences between the normal and the operated side have been compared to those found between the two sides in the control animals. The most important result is the demonstration that after cortical ablations the intralaminar nuclei show not only chromatolytic or atrophic changes of their cells but also a true cell loss. These reactions are qualitatively similar to those observed in the specific nuclei of the thalamus, the only difference being a quantitative one. As a consequence it can be suggested that some intralaminar nuclei project to certain areas of the cerebral cortex which also receive projections from one or other specific thalamic nucleus. A large essential connection of the intralaminar nuclei, in particular the nucleus centralis medialis, with subcortical structures is confirmed.

Animals↗