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Biomedical subjects

M Leone

Publications and source records attributed to M Leone.

At least 91 records · Page 5Linked to original sources
PubMed2000

Prevention of pulmonary thromboembolism by NCX 4016, a nitric oxide-releasing aspirin.

We studied the antithrombotic activity of 2-acetoxybenzoate 2-[1-nitroxy-methyl]-phenyl ester (NCX 4016), a novel nitric oxide (NO)-releasing aspirin derivative, in vivo in different animal models of platelet-dependent and independent pulmonary thromboembolism and compared it with that of aspirin. NCX 4016 protected mice from death induced by the intravenous (i.v.) injection of collagen plus epinephrine, of 9,11-dideoxy-11alpha, 9alpha-epoxymethano-prostaglandin F(2alpha) (U46619) and of thrombin while aspirin was only active against collagen plus epinephrine. The drop in platelet count and number of lung emboli were reduced by NCX 4016 more effectively than aspirin. NCX 4016 protected mice also from mechanical pulmonary embolism (i.v. injection of hardened rat red blood cells) while aspirin was ineffective. In rabbits, NCX 4016 significantly reduced the accumulation of [111In]oxine-labeled platelets in the pulmonary vasculature induced by collagen and by thrombin while aspirin produced reductions which were significant only versus collagen. In conclusion, NCX 4016 exerts a more pronounced antithrombotic activity than aspirin in vivo in two different animal species, largely due to a deeper inhibitory effect on platelets. NCX 4016 may represent a better antithrombotic agent than aspirin.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2000

Verapamil in the prophylaxis of episodic cluster headache: a double-blind study versus placebo.

The authors performed a double-blind, double-dummy study to compare the efficacy of verapamil with placebo in the prophylaxis of episodic cluster headache. After 5 days' run-in, 15 patients received verapamil (120 mg tid) and 15 received placebo (tid) for 14 days. The authors found a significant reduction in attack frequency and abortive agents consumption in the verapamil group. Side effects were mild. These findings provide objective evidence for the effectiveness of verapamil in episodic cluster headache prophylaxis.

Adult↗
PubMed2000

Heme symmetry, vibronic structure, and dynamics in heme proteins: ferrous nicotinate horse myoglobin and soybean leghemoglobin.

We report the visible and Soret absorption bands, down to cryogenic temperatures, of the ferrous nicotinate adducts of native and deuteroheme reconstituted horse heart myoglobin in comparison with soybean leghemoglobin-a. The band profile in the visible region is analyzed in terms of vibronic coupling of the heme normal modes to the electronic transition in the framework of the Herzberg-Teller approximation. This theoretical approach makes use of the crude Born-Oppenheimer states and therefore neglects the mixing between electronic and vibrational coordinates; however, it takes into account the vibronic nature of the visible absorption bands and allows an estimate of the vibronic side bands for both Condon and non-Condon vibrational modes. In this framework, an x-y splitting of the Q transition for native and deuteroheme reconstituted horse myoglobin is clearly assessed and attributed to electronic perturbations that, in turn, are caused by a reduction of the typical D(4h) symmetry of the system due to heme distortions of B(1g)-type symmetry and/or to an x-y asymmetric position of the nicotinate ring; in deuteroheme reconstituted horse myoglobin the asymmetric heme peripheral substituents add to the above effect(s). On the contrary, in leghemoglobin-a no spectral splitting upon nicotinate binding is observed, pointing to a planar heme configuration in which only distortions of A(1g)-type symmetry are effective and to which the nicotinate ring is bound in an x - y symmetric position. The local dynamic properties of the heme pocket of the three proteins are investigated through the temperature dependence of spectral line broadening. Leghemoglobin-a behaves as a softer matrix with respect to horse myoglobin, thus validating the hypothesis of a looser heme pocket conformation in the former protein, which allows a nondistorted heme configuration and a symmetric binding of the bulky nicotinate ligand.

Animals↗
PubMed2000

Two new SUNCT cases responsive to lamotrigine.

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) is a rare and debilitating headache form generally unresponsive to treatment. Following a recent report of a SUNCT patient who responded to lamotrigine, we tried this drug in two new SUNCT patients, reported here. In both cases prophylaxis was successful, suggesting lamotrigine might be the first effective treatment for this rare and debilitating headache syndrome.

Aged↗
PubMed2000

Metabolic effects of L-carnitine on prepubertal rat Sertoli cells.

The role of carnitine on Sertoli cell metabolism was investigated. Carnitine effects on Sertoli cell lipid metabolism were evaluated by measuring the intracellular levels of non-esterified fatty acids (NEFA) and ketone bodies. The concentration of NEFA in Sertoli cell cultured in the presence of carnitine is significantly reduced as compared to control, while, no significant changes were observed in the concentration of ketone bodies. The functional parameters evaluated to assess the influence of carnitine on Sertoli cell carbohydrate metabolism, i.e., lactate and pyruvate production, lactate dehydrogenase activity and hexose transport, were all significantly increased following carnitine in vitro supplementation. Thus, carnitine appears to drive Sertoli cell intermediary metabolism in an intimately interrelated way, stimulating both fatty acid breakdown and glycolysis. Our results indicate that Sertoli cells are a possible target for a widespread metabolic action of carnitine and strongly support the involvement of carnitine in the regulation of Sertoli cell functions which are related with germ cell "nutrition", convincingly suggesting a direct influence of the compound at testis level.

Animals↗
PubMed2000

Effect of norepinephrine on the outcome of septic shock.

OBJECTIVE: Despite increasingly sophisticated critical care, the mortality of septic shock remains elevated. Accordingly, care remains supportive. Volume resuscitation combined with vasopressor support remains the standard of care as adjuvant therapy, and many consider dopamine to be the pressor of choice. Because of fear of excessive vasoconstriction, norepinephrine is considered to be deleterious. The present study was designed to identify factors associated with outcome in a cohort of septic shock patients. Special attention was paid to hemodynamic management and to the choice of vasopressor used, to determine whether the use of norepinephrine was associated with increased mortality. DESIGN: Prospective, observational, cohort study. SETTING: Intensive care unit of a university hospital. PATIENTS: Ninety-seven adult patients with septic shock. MEASUREMENTS AND MAIN RESULTS: Data from these patients were examined to select variables independently and significantly associated with outcome during the hospital stay. Nineteen clinical, biological, and hemodynamic variables were collected at study entry or during the first 48-72 hrs and analyzed for each patient. A stepwise logistic regression analysis and a model building strategy were used to identify variables independently and significantly associated with outcome. The overall hospital mortality was 73% (71 patients). Five variables were significantly associated with outcome. One factor was strongly associated with a favorable outcome: the use of norepinephrine as part of the hemodynamic support of the patients. The 57 patients who were treated with norepinephrine had significantly lower hospital mortality (62% vs. 82%, p < .001; relative risk = 0.68; 95% confidence interval = 0.54-0.87) than the 40 patients treated with vasopressors other than norepinephrine (high-dose dopamine and/or epinephrine). Four variables were associated with a poor outcome and significantly higher hospital mortality: pneumonia as a cause of septic shock (82% vs. 61%, p < .03; relative risk = 1.47; 95% confidence interval = 1.07-1.77), organ system failure index < or = 3 (92% vs. 60%, p < .001; relative risk = 1.47; 95% confidence interval = 1.17-1.82), low urine output at entry to the study (88% vs. 60%, p < .01; relative risk = 1.44; 95% confidence interval = 1.06-1.87), and admission blood lactate concentration > 4 mmol/L (91% vs. 63%, p < .01; relative risk = 1.60; 95% confidence interval = 1.27-1.84). CONCLUSIONS: Our results indicate that the use of norepinephrine as part of hemodynamic management may influence outcome favorably in septic shock patients. The data contradict the notion that norepinephrine potentiates end-organ hypoperfusion, thereby contributing to increased mortality. However, the present study suffers from some limitation because of its nonrandomized, open-label, observational design. Hence, a randomized clinical trial is needed to clearly establish that norepinephrine improves mortality of patients with septic shock, as compared with high-dose dopamine or epinephrine. Pneumonia as the cause of septic shock, high blood lactate concentration, and low urine output on admission are strong indicators of a poor prognosis. Multiple organ failure is confirmed as a reliable predictor of mortality in septic patients.

Female↗
PubMed2000

High adenosine plasma concentration as a prognostic index for outcome in patients with septic shock.

OBJECTIVE: Sepsis and septic shock are a common cause of mortality in critically ill patients. Many substances have been implicated in the pathophysiology of these syndromes. We postulated that adenosine may be implicated in the sepsis- or septic shock-induced blood pressure failure. Indeed, this nucleoside is a strong endogenous vasodilating agent released by endothelial cells and myocytes under circumstances of metabolic stress, such as during critical illness. DESIGN: A prospective, comparative observational study. SETTING: The adult intensive care unit of a tertiary care university hospital. PATIENTS: We measured adenosine plasma concentration (APC) in patients with severe sepsis (n = 11), in patients with septic shock (n = 14), in patients with hemorrhagic traumatic shock (n = 14), and in 12 healthy volunteers. APC was evaluated every 12 hrs over 3 days. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: At study entry, we found that APC was higher in patients with septic shock (mean +/- so = 8.4 +/-3.5 micromol/L) than in patients with hemorrhagic traumatic shock (1.1 +/- 0.6 micromol/L) and controls (0.8 +/- 0.3 micromol/L). Intermediate values (3.9 +/- 1.9 micromol/L) were found in patients with severe sepsis. APC in patients with traumatic shock did not differ from controls. In the course of the hospitalization, for both sepsis and septic shock patients, APC decreased significantly but remained higher than controls 72 hrs after entry into the study. In the septic shock group, APC was significantly higher in the nonsurvivor group (n = 6) than in the survivor group (n = 8), whatever the time of sample collection and assay. CONCLUSIONS: High adenosine plasma concentrations are found in patients with septic shock but not during traumatic shock, or in healthy volunteers. Intermediate values of circulating adenosine are found in patients with severe sepsis. APC may be a prognostic index for outcome in septic patients, with much higher values being found in nonsurvivors.

Adenosine↗
PubMed1998

Properties of human hemoglobins with increased polarity in the alpha- or beta-heme pocket. Carbonmonoxy derivatives.

The spectroscopic, conformational, and functional properties of mutant carbonmonoxy hemoglobins in which either the beta-globin Val67(E11) or the alpha-globin Val62(E11) is replaced by threonine have been investigated. The thermal evolution of the Soret absorption band and the stretching frequency of the bound CO were used to probe the stereodynamic properties of the heme pocket. The functional properties were investigated by kinetic measurements. The spectroscopic and functional data were related to the conformational properties through molecular analysis. The effects of this nonpolar-to-polar isosteric mutation are: (i) increase of heme pocket anharmonic motions, (ii) stabilization of the A0 conformer in the IR spectrum, (iii) increased CO dissociation rates. The spectroscopic data indicate that for the carbonmonoxy derivatives, the Val --> Thr mutation has a larger conformational effect on the beta-subunits than on the alpha-subunits. This is at variance with the deoxy derivatives where the conformational modification was larger in the heme pocket of the alpha-subunit (Cupane, A., Leone, M., Militello, V., Friedman, R. K., Koley, A. P., Vasquez, G. P., Brinigar, W. S., Karavitis, M., and Fronticelli, C. (1997) J. Biol. Chem. 272, 26271-26278). These effects are attributed to a different electrostatic interaction between Ogamma of Thr(E11) and the bound CO molecule. Molecular analysis indicates a more favorable interaction of the bound CO with Thr Ogamma in the beta-subunit heme pocket.

Carboxyhemoglobin↗
PubMed1998

5-HT1A receptor hypersensitivity in migraine is suggested by the m-chlorophenylpiperazine test.

Involvement of the cerebral serotoninergic system has been invoked to explain the origin of the pain and the vascular phenomena in migraine. To further investigate the type of cerebral serotonin receptors that may be altered in migraine, the prolactin (PRL) and cortisol responses to m-chlorophenylpiperazine (mCPP), a selective 5-HT1A,-5-HT(2A/C) receptor agonist, were monitored in 12 patients suffering from migraine without aura and in 14 matched healthy controls. Each subject underwent two challenges, one with mCPP (0.5 mg/kg) and the other with placebo (orally) using a double-blind crossover design. Anxiety level was measured by the State Trait Anxiety Inventory. Migraine patients had a greater PRL response to mCPP (p = 0.05) and greater anxiety (p < 0.01) than controls; cortisol response to mCPP did not differ suggesting that 5-HT2C receptors are normal in migraine. Augmented PRL response to mCPP could derive from 5-HT1A receptor hypersensitivity, perhaps as as a consequence of anxiety due to pain expectation. Cerebral 5-HT1A hypersensitivity could also explain the increased occurrence of migraine attacks during anxiety.

Adult↗
PubMed1998

Cost- and time-sparing simplified conformal therapy for prostate cancer: is it feasible?

PURPOSE: It was hypothesized that using a simplified technique of volumes profiles determination (STVPD) based on CT data sets (correlate and projection) would increase the target dose without increasing the bladder and rectal dose obtained by conventional simulation techniques. To test this hypothesis, patients referred for radical radiation treatment for prostate carcinoma were prospectively evaluated by performing treatment planning using standard simulation, with (SSB) and without corner blocks (SSWB), STVPD, and 3D beam's eye view. METHODS AND MATERIALS: Twenty-one patients with prostate carcinoma (stage B: 7; stage C: 14) underwent four treatment planning procedures where the field arrangement was defined by standard simulation (SSB and SSWB), STVPD, and 3D beam's eye view (BEV) with a four field (10 MV photons) box technique. Dose-volume histograms (DVHs) for the planning target volume (PTV), bladder, and rectum (relatives to the four techniques) were generated for all patients and compared; average percentage dose to the bladder and rectum were also calculated. RESULTS: STVPD and 3D BEV treated an increased percentage of PTV at 95% isodose level, in comparison to standard simulation (with and without blocks). No statistically significant differences were found between the two techniques. A significant reduction of irradiated bladder volume was found between 3D BEV and STVPD versus simulation with and without blocks (mean percentage dose: 77.3%, 81.8%, 93.5%, and 92.6% respectively). No marked differences were recorded in rectal irradiation (mean percentage dose: 53.1%, 53.7%, 51.9%, and 50.2% respectively). Time required for treatment planning (excluding CT scan and definitive simulation) was less than 15 minutes for STVPD and more than 120 minutes for 3D BEV. CONCLUSION: Our results confirm the inadequacy of standard simulation. It is possible, with conformal therapy, to increase the dose to the PTV, decreasing the irradiated volume of the bladder. The absence of sparing effect in the rectum is discussed. Using a box technique, STVPD can be used routinely to define the PTV in patients with prostate cancer, reducing the time required for treatment planning, with dosimetric results similar to those of 3D BEV.

Aged↗
PubMed1998

Fourier transform infrared analysis of the interaction of azide with the active site of oxidized and reduced bovine Cu,Zn superoxide dismutase.

Binding of azide to the native and arginine-modified bovine Cu,Zn superoxide dismutase in the oxidized and reduced form and to the copper-free derivative has been investigated by Fourier transform infrared spectroscopy. The antisymmetric stretching band of the azide is shifted to higher energy upon coordination to the copper atom of the oxidized form of the native enzyme. Similar spectral changes occur upon interaction of the anion with the Cu-diethylenetriamine model compound. On the other hand, interaction of azide with the native reduced form of the enzyme results in a band shift toward lower energy with respect to the free anion band. The same shift is observed after reaction of the azide with free lysine or arginine but not when it is reacted with other amino acid residues. The antisymmetric band of the azide is not perturbed by addition of the reduced arginine-modified enzyme; it is likely shifted toward higher energy upon addition of oxidized arginine-modified enzyme while it is again shifted toward lower energy in the presence of the copper-free derivative of the unmodified enzyme. It is concluded that azide does not directly coordinate to the copper in the reduced form of Cu,Zn superoxide dismutase but it remains in the active-site pocket in electrostatic interaction with the guanidinium group of Arg141, which is an invariant residue in this class of enzymes.

Animals↗
PubMed1998

Pharmacological and behavioral treatment of pediatric migraine and tension-type headache.

The problem concerning the treatment of pediatric headache has been the object of several recent reports. Some of the same medications used to treat adult headache problems are also utilized with children but usually at smaller dosages and in different combinations. The recent application of behavioral approaches, in particular biofeedback, for treatment of children's headaches has been an effective alternative to drugs without the problematic and dangerous side effects of pharmacological treatments. The purpose of this review is to give some indications about the most common pharmacological therapies for migraine and tension-type headache in children, and also to discuss the use of behavioral therapies, in particular biofeedback, as excellent alternatives to drugs.

Acute Disease↗
PubMed1998

Type II neurofibromatosis presenting as quadriceps atrophy.

A young woman aged 26 years presented with atrophy of the left quadriceps progressing over one year. Magnetic resonance imaging (MRI) showed a large lesion of the lumbar plexus compatible with neurinoma. Cerebral MRI revealed a lesion in the right eighth cranial nerve also compatible with neurinoma. On further questioning of the patient, it was learned that her mother had undergone surgery twice for acoustic neurinoma. Type II neurofibromatosis was diagnosed from the basis of clinical picture, neuroimaging findings and family history. This case is unusual for the lack of central nervous system (CNS) symptoms. Expansive radicular lesions compatible with neurinoma should prompt cerebral MRI. Regular examination of family members at risk and early diagnosis can decrease the high mortality associated with this condition.

Adult↗
PubMed1998

A review of the treatment of primary headaches. Part II: Tension-type headache.

This paper reviews pharmacological and other approaches currently used to treat tension-type headache (TTH), and examines aspects of the classification and pathogenesis of this common complaint. Accurate diagnosis is essential before treatment is prescribed and should involve complete history taking, thorough neurological examination and evaluation of possible associated factors. The most frequently used drugs for the acute treatment of TTH are non-steroidal anti-inflammatory drugs (NSAIDs) of which only some have been shown to be efficacious in placebo-controlled trials. Amitriptyline remains the first choice treatment for prophylaxis. Other antidepressants, muscle relaxants and benzodiazepines may be used, but few have been evaluated adequately in placebo-controlled trials. Biofeedback and relaxation training, demonstrated efficacious by controlled studies, may be used when the aim is to avoid the side effects of pharmacological treatment.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

Structural and dynamic properties of the homodimeric hemoglobin from Scapharca inaequivalvis Thr-72-->Ile mutant: molecular dynamics simulation, low temperature visible absorption spectroscopy, and resonance Raman spectroscopy studies.

Molecular dynamics simulations, low temperature visible absorption spectroscopy, and resonance Raman spectroscopy have been performed on a mutant of the Scapharca inaequivalvis homodimeric hemoglobin, where residue threonine 72, at the subunit interface, has been substituted by isoleucine. Molecular dynamics simulation indicates that in the Thr-72-->Ile mutant several residues that have been shown to play a role in ligand binding fluctuate around orientations and distances similar to those observed in the x-ray structure of the CO derivative of the native hemoglobin, although the overall structure remains in the T state. Visible absorption spectroscopy data indicate that in the deoxy form the Soret band is less asymmetric in the mutant than in the native protein, suggesting a more planar heme structure; moreover, these data suggest a similar heme-solvent interaction in both the liganded and unliganded states of the mutant protein, at variance with that observed in the native protein. The "conformation sensitive" band III of the deoxy mutant protein is shifted to lower energy by >100 cm-1 with respect to the native one, about one-half of that observed in the low temperature photoproducts of both proteins, indicating a less polar or more hydrophobic heme environment. Resonance Raman spectroscopy data show a slight shift of the iron-proximal histidine stretching mode of the deoxy mutant toward lower frequency with respect to the native protein, which can be interpreted in terms of either a change in packing of the phenyl ring of Phe-97, as also observed from the simulation, or a loss of water in the heme pocket. In line with this latter interpretation, the number of water molecules that dynamically enters the intersubunit interface, as calculated by the molecular dynamics simulation, is lower in the mutant than in the native protein. The 10-ns photoproduct for the carbonmonoxy mutant derivative has a higher iron-proximal histidine stretching frequency than does the native protein. This suggests a subnanosecond relaxation that is slowed in the mutant, consistent with a stabilization of the R structure. Taken together, the molecular dynamics and the spectroscopic data indicate that the higher oxygen affinity displayed by the Thr-72-->Ile mutant is mainly due to a local perturbation in the dimer interface that propagates to the heme region, perturbing the polarity of the heme environment and propionate interactions. These changes are consistent with a destabilization of the T state and a stabilization of the R state in the mutant relative to the native protein.

Animals↗
PubMed1998

[Nasogastric tube: intratracheal malposition and entrapment in a bronchial suture].

We report the unrecognized accidental intratracheal insertion of a nasogastric tube, following endotracheal intubation in a patient scheduled to undergo right lower lobectomy for carcinoma. After surgery, which had an unremarkable course, the trachea was extubated. However, the gastric tube was entrapped and attempts to withdraw it elicited fits of coughing. A chest X-ray showed the tube malpositioned in the right bronchus. A fibreoptic bronchoscopy did not permit removal of the tube extremity which was embedded in the bronchial suture. Finally an additional thoracotomy was required to withdraw the tube securely. The manifestations of the intratracheal position of a nasogastric tube as well as the preventive and diagnostic measures of such a complication are considered.

Aged↗