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Biomedical subjects

L Murri

Publications and source records attributed to L Murri.

At least 55 records · Page 3Linked to original sources
PubMed2001

Characteristics of cerebral microembolism during carotid stenting and angioplasty alone.

BACKGROUND: Cerebral microembolism has often been documented by transcranial Doppler imaging during carotid angioplasty and stenting. However, few data are available about its characteristics during the 2 different kinds of procedure. OBJECTIVES: To compare the incidence of microemboli occurring during angioplasty alone with that during stenting in the different phases of the procedures and to relate it to periprocedural cerebrovascular complications. PATIENTS AND METHODS: Thirty-eight patients underwent 41 procedures (15 angioplasty alone and 26 stenting) for symptomatic carotid stenoses of 70% or more. Transcranial Doppler monitoring was performed to detect microemboli in the middle cerebral artery during 3 phases of the procedure: (1) guidewire crossing, (2) first dilatation in case of angioplasty alone or stent release with predilatation if performed, and (3) further dilatation. RESULTS: Microemboli occurred in all cases in phase 1 of the procedure but less frequently in the arteries treated with stenting when compared with those treated with angioplasty alone in phase 2 and particularly (P<.02) in phase 3. The mean number of microemboli was highest in phase 2, predominant (P<.05) during angioplasty alone, and particularly reduced (P<.02) in phase 3 during the stenting procedures. During 2 (5%) of the 41 procedures, cerebrovascular complications occurred in phase 1, with the number of microemboli being higher than mean values. CONCLUSIONS: Cerebral microembolism is a very common event, especially during guidewire crossing and angioplasty alone compared with stenting. Further studies concerning the prognostic significance of this are advisable.

Aged↗
PubMed2001

The importance of nasal resistance in obstructive sleep apnea syndrome: a study with positional rhinomanometry.

The importance of nasal obstruction in the pathogenesis of obstructive sleep apnea syndrome (OSAS) has not yet been totally defined. Numerous studies have reported an association between nasal obstruction and OSAS, but the precise nature of this relationship remains to be clarified. This study was undertaken to evaluate the prevalence of nasal obstruction disorders in a group of OSAS patients. For this purpose, we analyzed the nasal resistance of 36 OSAS patients by performing a traditional basal anterior active rhinomanometry test (AAR) and a positional AAR, with the patient in a supine position. Seven patients had a pathologic nasal resistance in the seated position that increased further in the supine position; 9 patients had normal resistance in the seated position but a pathologic resistance in the supine position. In 20 patients, nasal resistance was normal in both positions. No statistically significant differences in the degree of apnea/hypopnea index (AHI) was found between the 20 patients with normal positional AAR and the 16 with pathologic positional AAR (p = 0.13). Moreover, no statistically significant differences in the degree of AHI was found between the 7 patients with pathologic basal and positional AAR and the 9 patients with normal basal AAR and pathologic positional AAR (p = 0.38).

Adult↗
PubMed2001

Extended thymectomy in myasthenia gravis: a team-work of neurologist, thoracic surgeon and anaesthesist may improve the outcome.

OBJECTIVE: We reviewed our overall experience on 163 patients, affected by myasthenia gravis, who underwent thymectomy between 1976 and 1998. A comparison between the oldest series of 72 patients (January 1976-December 1992), referred by various neurologists and operated on through different approaches, and the last 91 patients (January 1993-December 1998), taking part in a strict diagnostic-therapeutical programme, was made. METHODS: Anagraphic data, duration of symptoms, the surgical approach, necessity of respiratory assistance, the hospital stay, histopathological findings, preoperative and postoperative Osserman classification, as well as medications, were globally analyzed and then compared in the two groups. RESULTS: Significant differences in the length of hospitalization (8.7 days vs. 4.2 days; P=0.00001) and in the prolonged intubation rate (18 vs. 0; P<0.000001) were observed in the most recent series. Patients in the pre-operative Osserman stage I and operated on in the second period had a higher complete remission rate at the univariate analysis (P<0.001 and P<0.0001, respectively). At the multivariate analysis the only parameter which affected the outcome was to be operated on in the second period (P<0.01). CONCLUSIONS: Our experience confirms the role of the extended thymectomy in the treatment of myasthenia gravis. Whenever an extended thymectomy was performed through a complete sternotomy it was a quick procedure, with short hospitalization and acceptable cosmetic results. A careful pharmacological control of the myasthenic symptoms and the presence of team-work among neurologist, thoracic surgeon and anaesthesist in the peri-operative setting reduce the incidence of complications and might increase the efficacy of the thymectomy.

Adolescent↗
PubMed2001

Neurophysiological evaluation of vigilance in epileptic patients on monotherapy with lamotrigine.

OBJECTIVE: Limited research has focused to date on daytime sleepiness in epileptic patients treated with either conventional or newer antiepileptic drugs. We evaluated the level of vigilance in 15 consecutive, newly diagnosed and never medicated adult epileptic patients, receiving initial monotherapy with lamotrigine (LTG). METHODS: Patients underwent the Multiple Sleep Latency Test (MSLT), visual reaction times (VRT) and Stanford Sleepiness Scale (SSS) on two separate occasions, i.e. before and 2 months after LTG treatment. A group of 15 age-matched healthy volunteers was taken as control. RESULTS: At baseline, mean sleep latencies on the MSLT were comparable in epileptic patients and in controls. In patients, 2 months after monotherapy with LTG 200 mg/day, MSLT scores did not significantly change as compared with pre-treatment values. Accordingly, subjective evaluation of vigilance by the SSS and psychomotor performance by VRT were superimposable in controls and in untreated patients, and did not change in patients after LTG treatment. CONCLUSIONS: These results suggest that in adult, newly diagnosed epileptic patients initial monotherapy with LTG does not impair vigilance.

Adult↗
PubMed2001

Circulating levels of allopregnanolone, an anticonvulsant metabolite of progesterone, in women with partial epilepsy in the postcritical phase.

PURPOSE: Several lines of evidence indicate that there exists a relation between ovarian hormones and epilepsy. Estrogens decrease seizure threshold and increase brain excitability, whereas progesterone has an inhibitory effect and reduces epileptiform activity. Recently considerable interest has turned to neuroactive steroids, a group of progesterone metabolites, as endogenous modulators of excitability of the central nervous system (CNS). Their ability to alter neuronal firing rapidly occurs through interaction with gamma-aminobutyric acid (GABA) A receptor complex. In a previous experience, serum allopregnanolone (3alpha-OH-5alpha-pregnan-20-one) levels were measured in 15 women with partial epilepsy in the intercritical phase, and no significant differences were found between patients and control subjects. METHODS: To find out if there are changes in serum allopregnanolone levels after epileptic seizure, blood samples were drawn immediately, 15 min, and 6 h after a seizure in seven fertile females with partial epilepsy. RESULTS: The most interesting finding is that allopregnanolone increases in serum during the first 15 min after partial seizures (p < 0.05) and decreases after 6 h. CONCLUSIONS: These data are consistent with a role for allopregnanolone in the control of neuronal excitability and seizures.

Adult↗
PubMed2001

Equiluminant red-green and blue-yellow VEPs in multiple sclerosis.

The primate visual system is composed by two color-opponent pathways--red-green (R-G) and blue-yellow (B-Y)--subserved by the so-called parvo- and koniocellular streams respectively. The authors' aim was to compare the relative involvement of chromatic visual subsystems in multiple sclerosis (MS). In 30 MS patients with different forms of MS they recorded visual evoked potentials (VEPs) to onset (300 msec) and offset (700 msec) of equiluminant R-G and B-Y sinusoidal gratings of different contrast (90% and 25%). Equiluminance was established psychophysically by establishing the R-G and the B-Y color ratio at which chromatic gratings alternating at 15 and 10 Hz respectively had minimum visibility. The negative wave at stimulus onset with a peak latency of 120 to 160 msec was evaluated. Ordinary VEPs to luminance (LUM) contrast (black-white reversing checkerboards of 15' check size and 50% contrast) were also recorded for comparison. Latencies of R-G VEPs were abnormal in 53.3% and 58.3% of patients at 90% and 25% contrast respectively, whereas abnormal B-Y VEPs were 56.6% and 48.3%. Latencies of LUM VEPs were abnormal in 45% of patients. Interocular latency asymmetries were abnormal in 59.2% and 33.3% of patients for R-G, and 51.8% and 62.9% for B-Y. Latency asymmetries for LUM VEP were abnormal in 46.4% of patients. The higher rate of VEP abnormalities found with equiluminant chromatic stimuli compared with achromatic stimuli confirms the general vulnerability of color-opponent visual pathways in MS, even if the number of patients with abnormal findings was not significantly different when both test conditions were compared. VEPs to R-G and B-Y equiluminant stimuli appear to be involved approximately to the same extent.

Adolescent↗
PubMed2000

Paroxetine in Parkinson's disease: effects on motor and depressive symptoms.

Selective serotonin reuptake inhibitors have been used in the treatment of depression in patients with PD. Conflicting data as to whether selective serotonin reuptake inhibitors worsen parkinsonian motor symptomatology have been reported. In this study, the additional 6 months therapy with paroxetine 20 mg/d in a group of depressed patients with PD did not modify parkinsonian motor function (Unified Parkinson's Disease Rating Scale scores); however, in one patient, fully reversible worsening of tremor was observed. Depression, as evaluated by Beck Depression Inventory and Hamilton Depression Rating Scale, improved from baseline to final visit (p < 0.05 by analysis of variance).

Aged↗
PubMed2000

Long-term interferon beta-1b therapy for MS: is routine thyroid assessment always useful?

BACKGROUND: The authors previously reported on the development of thyroid dysfunction and autoimmunity during 1-year treatment of patients with MS with interferon-beta 1b (IFN beta-1b). OBJECTIVE: To evaluate the evolution of incident thyroid disease and the possible development of more thyroid disease during longer term therapy. PATIENTS: The authors studied 31 patients (aged 34 +/- 7 years; 21 women) with relapsing-remitting MS during 3 years of IFN beta-1b treatment. Systematic thyroid assessment was performed every 3 or 6 months, depending on the development of thyroid disease. RESULTS: After the first year of IFN beta-1b treatment, no further cases of thyroid disease were observed. Among the six patients with early incident subclinical hypothyroidism, thyroid dysfunction persisted only in those with baseline autoimmune thyroiditis (n = 2). The three patients who developed transient hyperthyroidism remained euthyroid throughout the treatment course. A positive autoantibody titer was continually detected in only two out of five patients without baseline autoimmunity. CONCLUSIONS: The risk of thyroid disease seems related to IFN beta-1b treatment during the first year only, particularly in patients with preexisting thyroiditis. Furthermore, incident thyroid dysfunction is generally transient and mild in degree. Indeed, we recommend a routine systematic thyroid assessment only in patients with baseline thyroiditis. During the first year of therapy, serum thyroid-stimulating hormone measurement should suffice as first line test; a systematic thyroid assessment is only useful for those patients with incidental and persistent dysfunction. Further studies with many patients will be necessary to confirm our suggestions as broad clinical guidelines.

Adult↗
PubMed2000

Potential involvement of ubiquinone in myotonic dystrophy pathophysiology: new diagnostic approaches for new rationale therapeutics.

An impairment of mitochondrial function may contribute to the pathophysiology of myotonic dystrophy (MyD). Coenzyme Q10 (CoQ10) deficiency has been previously observed, even if in a restricted sample of patients. The aim of this investigation was to obtain more information about coenzyme Q10 and its relationships to the aerobic metabolism in a group of MyD patients. Serum CoQ10 appeared significantly reduced with respect to normal controls: 0.93 +/- 0.22 vs. 1.58 +/- 0.28 micrograms/ml (p < 0.05). Moreover, the results demonstrated an inverse tendency between CoQ10 levels and the CTG expansion degree. Basal blood lactate levels were significantly higher than controls (p < 0.05). A borderline inverse correlation between CoQ10 and lactate, corresponding to lactate threshold, was found. These data suggest a possible role of CoQ10 in the pathogenesis of MyD, which may be mediated by mechanisms of cellular damage common to the oxidative pathway. Therapeutic strategies may be devised by virtue of this rationale.

Coenzymes↗
PubMed2000

Peripheral-type benzodiazepine receptors in human blood cells of patients affected by migraine without aura.

The kinetic parameters at equilibrium of peripheral benzodiazepine receptors in platelets, lymphocytes and granulocytes of 15 patients affected by migraine without aura were tested using [3H]PK 11195, a specific radioligand for this receptor and compared with the same number of healthy controls: a statistically significant increase (platelets 212%, lymphocytes 203%, granulocytes 171%, as absolute percentage) in the maximal number of binding sites (B(max)) in all three patient samples, compared with healthy controls was detected; on the contrary, the values of the dissociation constant (K(d)) at equilibrium do not show any statistically significant variations between the two groups. These data further confirm the presence of peripheral biochemical alterations in migraine without aura. As peripheral benzodiazepine receptors appear to be involved in the regulation of the mitochondrial respiratory chain, the observed increase in B(max) might be related to the mitochondrial anomalies found in migraine disorders.

Adult↗
PubMed2000

Effects of aerobic training on lactate and catecholaminergic exercise responses in mitochondrial myopathies.

The aim of this study was to evaluate the effects of an aerobic training program on the metabolic and sympathetic responses to exercise in 12 patients with mitochondrial myopathies. A 10-week course of aerobic training, consisting of supervised exercise every other day on an electrically braked pedal-rate bicycle ergometer was prescribed to each patient and four healthy controls. Venous lactate, epinephrine (EP) and norepinephrine (NEP) levels were assessed at baseline and after the aerobic training by means of constant-workload exercise performed at near lactate threshold (LT). In patients, a decrease in exercise peak values, significant for lactate (-38.6%, P < 0.01) but not for catecholamines (EP: -26.0%, NEP: -22.1%) was observed after training, findings confirmed by the lactate/EP and lactate/NEP area ratios. The results show that lactate accumulation during exercise is decreased after aerobic training in mitochondrial myopathies and that the effect is partially dissociated from the catecholaminergic response. This in turn suggests that the lactate decrease can be explained, at least in part, by the improved muscle oxidative metabolism consequent to the proposed training program.

Adult↗
PubMed2000

Transient autonomic nervous system dysfunction during hyperacute stroke.

Forty-four patients suffering a stroke for the first time were examined within 10 h of the onset of symptoms; the tests performed on their admission to hospital, and thereafter on the third and seventh day, were 24-h Holter EKG with spectral analysis of heart rate variability, evaluation of arterial blood pressure and the levels of catecholamine in the blood and 24-h urine. The dynamic EKG on admission revealed that 31 (70.5%) out of the 44 patients already had arrhythmia. These alterations were observed in 9 (75%) out of 12 haemorrhagic patients with a significant (P < 0.05) prevalence compared to 22 (68.8%) of the 32 ischaemic ones. Arrhythmia showed up in 16 (76.2%) out of 21 cases with right hemisphere lesions and in 12 (63.2%) out of 19 cases of left hemisphere lesions; this difference was also significant (P<0.05). Arrhythmia was still present in 19 (43.2%) patients after 3 days and only in 2 (6.5%) patients after 7 days. The spectral analysis parameters on admission and after 3 days were significantly (P < 0.05) modified in patients with stroke plus arrhythmia, compared to patients with stroke alone and to control subjects, whereas no further differences were observed on the seventh day. Moreover, the percentage of patients with arterial hypertension and high levels of catecholamine greatly decreased from the third day onwards. A transient autonomic nervous system imbalance with prevalent sympathetic activity may justify this cardiovascular impairment during the hyperacute phase of stroke.

Acute Disease↗
PubMed2000

Pharmacological prophylaxis of post-traumatic epilepsy.

Early and late epileptic seizures are a frequent complication of severe head traumas. The administration of anticonvulsant drugs immediately after head injury is commonly implemented as a prophylactic measure; however, there is a lack of consensus on the usefulness of prophylaxis with anticonvulsants for the prevention of late post-traumatic epilepsy (PTE). The inconsistent evidence accumulated so far from clinical studies, most nonrandomised and uncontrolled in design, and the limited knowledge of the processes underlying post-traumatic epileptogenesis, do not warrant empirical pharmacological prophylaxis with long term administration of conventional anticonvulsants. Phenytoin and phenobarbital (phenobarbitone) are used to a large extent in this indication. As a general rule, a benefit/risk analysis in individual patients should drive prophylactic drug prescription in PTE as it can have potential detrimental effects on a patient's recovery. New compounds, such as free-radical scavengers and antiperoxidants, show encouraging experimental results, but their clinical use is still very limited.

Animals↗
PubMed1999

Cortical silent period in patients with amyotrophic lateral sclerosis.

Transcranial magnetic stimulation (TMS) during a muscle contraction induces a motor-evoked potential (MEP) in the skeletal muscle followed by a cessation of EMG activity, the cortical silent period (C-SP). The C-SP is a useful parameter to indicate the activation of the motor system. Accurate determination of the C-SP can be important in amyotrophic lateral sclerosis (ALS), a progressive disorder of unknown etiology characterised by degeneration of upper and lower motor neurons. The aim of this study was to evaluate the sensitivity of C-SP as an index of motor system involvement, in ten patients affected by ALS, with a mean duration of the disease: 5. 5+/-3.4 months, by means of an objective computer-aided method to measure C-SP and its relationship to stimulation intensity. C-SP duration was significantly reduced in ALS patients compared to controls at low stimulation intensity corresponding to an MEP threshold increased by 15%. While in less severely affected patients C-SP duration approached control values at higher stimulation intensities (25 and 50% upper MEP threshold), in more severe ALS subjects it showed a further reduction, allowing them to be discriminated.

Aged↗
PubMed1999

Amplitude loss of electrically and magnetically evoked sympathetic skin responses in early stages of type 1 (insulin-dependent) diabetes mellitus without signs of dysautonomia.

The sympathetic skin responses following both electrical nerve (eSSRs) and magnetic (mSSRs) brain stimulations have been investigated in 19 insulin-dependent diabetic patients with no evidence of a peripheral neuropathy or dysautonomia and compared to those obtained in 10 age-matched healthy subjects. SSR was recorded from the right hand and foot, controlateral to the stimulated side. The main findings were amplitude loss and disappearance of the eSSR in 12/19 (63.2%) and 11/19 (57.9%) patients, occurring more frequently than the mSSR; 7/19 (36.8%) and 5/19 (26.3%) were recorded from the hand and foot, respectively. The SSR to electrical stimulation was significantly reduced in the upper and lower extremities (p < 0.0001) compared to control results, whereas latencies were normal to both stimulation modalities. Only in two cases the responses were absent from the foot, one following electrical stimulation and the other after magnetic stimulation. No correlation was found between the SSR and metabolic indexes of diabetes mellitus or conduction velocity studies. On the basis of these data an early impairment of afferent pathways may be postulated.

Adult↗
PubMed1999

Is lithium able to reverse neurological damage induced by vinca alkaloids? (Short communication).

Lithium (Li) actively antagonises the inhibiting action of vinca alkaloids on human leukocyte chemotaxis; it proved to be related to the activation of microtubular system, possibly mediated by its inhibiting effect on cyclic AMP. Vinca alkaloids induce peripheral neuropathy and muscle damage. The molecular basis of this neurotoxicity has not been fully explained, but a possible role of neurofibrillary degeneration has been reported. We studied both in animals and in humans, whether Li is able to antagonise vinca alkaloid neurotoxicity.

Adult↗
PubMed1999

Plaque surface and microembolic signals in moderate carotid stenosis.

We performed Transcranial Doppler Monitoring to detect microembolic signals (MES) in 47 patients with moderate (30%-69%) carotid stenosis proven by selective angiography. We compared the occurrence of MES with the clinical characteristics of stenosis (symptomatic or asymptomatic) and the angiographic plaque features (nonulcerated, deep ulceration, superficial ulceration, ulceration with flap, or ulceration without flap). For these cases there was no indication for endarterectomy, nevertheless we thought it would be useful to identify risk subgroups that might benefit from surgical treatment. MES were detected in 17.9% of the stenoses with a prevalence (p <. 01) in symptomatic cases (25%) compared to asymptomatic cases (14. 3%). There was a significant correlation of MES with plaque ulceration (p <.01) and particularly with ulceration without flap (p <.01). No difference between deep and superficial ulceration was observed. The availability of prospective data on this topic might be useful to select subgroups of patients with moderate carotid stenosis at risk for embolism.

Aged↗