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M Ferrero

Publications and source records attributed to M Ferrero.

At least 19 recordsLinked to original sources
PubMed2005

Experimental and theoretical study of a surface stabilized monolayer phase of nickel oxide on Pd(100).

A surface stabilized monolayer phase of nickel oxide, c(4 x 2)-Ni(3)O(4), has been found to grow epitaxially under reactive deposition conditions on Pd(100), in the presence of other adsorbed phases and in competition with them. High-quality scanning tunneling microscopy data are reported and discussed, including a detailed analysis of the defects and of the border morphology of this new phase. The data are discussed in the light of ab initio simulations of the electronic, energetic, and geometric properties of such a phase. A hybrid-exchange density functional theory approach has been used, and a slab model is adopted where palladium is simulated by a thin film covered on both sides by regular epilayers. A growth model has been developed that explains both the unusual stoichiometry of the phase and the observed defects.

Journal Article↗
PubMed2005

Insulin sensitivity is impaired in patients with migraine.

Several studies have shown the presence of a comorbidity between migraine and vascular diseases, like hypertension and stroke. The mechanisms of this comorbidity are unknown. Impaired insulin sensitivity has recently emerged as a risk factor for hypertension and stroke. We evaluated insulin sensitivity in 30 young, nonobese, nondiabetic, normotensive migraine patients and in 15 healthy controls. During the OGTT, glucose plasma concentrations were significantly higher in migraineurs than in controls. Insulin sensitivity, as measured by ISI-stumvoll and OGIS-180 indexes, was significantly altered in migraine. Our data show that insulin sensitivity is impaired in migraine and suggest a role for insulin resistance in the comorbidity between migraine and vascular diseases.

Adult↗
PubMed2005

Lack of association between the 3092 T-->C Clock gene polymorphism and cluster headache.

Recent studies suggested that genetic factors play a role in cluster headache (CH). However, the type and the number of genes involved in the disease are still unclear. We performed an association study in a cohort of Italian CH patients to evaluate whether a particular allele or genotype of the Clock gene would modify the occurrence and the clinical features of the disease. One hundred and seven CH patients, diagnosed according to the International Classification of Headache Disorders, 2nd Edition, (ICHD-II) criteria, and 210 healthy age, sex and ethnicity-matched controls were genotyped for the 3092 T-->C Clock gene polymorphism (also known as 3111 T-->C). Phenotype and allele frequencies were similarly distributed in CH patients and controls. The clinical features of the disease were not significantly influenced by different genotypes. In conclusion, our study suggests that the 3092 T-->C polymorphism of the Clock gene is unlikely to play an important role in cluster headache.

Adult↗
PubMed2004

A polymorphism of the hypocretin receptor 2 gene is associated with cluster headache.

Several polymorphisms of the hypocretin/orexin system genes were evaluated in 109 cluster headache patients and 211 controls. The 1246 G>A polymorphism of the gene was significantly different between cases and controls. Homozygosity for the G allele was associated with an increased disease risk (OR: 6.79, 95% CI, 2.25 to 22.99). The data suggest that the HCRTR2 gene or a linked locus significantly modulates the risk for cluster headache.

Adult↗
PubMed2003

Breath test is very reliable for diagnosis of Helicobacter pylori infection in real clinical practice.

AIMS: To determine the accuracy of the most common available tests for the diagnosis of Helicobacter pylori infection in an unselected and untreated population of patients. PATIENTS AND METHODS: Prospective study including 314 unselected patients from a population of 814 patients referred for upper endoscopy at one hospital. H. pylori infection was diagnosed by rapid urease test (RUT), histology, culture and 13C-urea-breath test (UBT) and serum IgG (EIA). H. pylori infection was defined as positive if culture or at least two of the other tests were positive. RESULTS: The prevalence of H. pylori infection in this population was 72%. The diagnostic test with the greatest combination of sensitivity (97%) and specificity (100%) was the UBT. EIA had a good sensitivity (96%), but it was the test with the least specificity (71%). RUT, histology and culture showed a high specificity (>98%) but a sensitivity lower than 90%. In elderly patients (>65 years old, n=120), UBT was also the test with the greatest combination of sensitivity (94%) and specificity (100%). CONCLUSIONS: In conditions of real clinical practice the 13C-urea-breath test is a reliable test for H. pylori diagnosis, both in young and elderly patients.

Adult↗
PubMed2003

Abnormal 5-HT1D receptor function in cluster headache: a neuroendocrine study with sumatriptan.

The purpose of this study was to assess the sensitivity of 5-HT(1D) receptors in patients with episodic cluster headache using sumatriptan as a pharmacological probe. The drug, a selective 5-HT(1B/1D) agonist, stimulates the secretion of growth hormone and inhibits the release of prolactin, adrenocorticotropic hormone (ACTH) and cortisol. These effects may be used to explore the function of serotonergic systems in vivo. We administered subcutaneous sumatriptan and placebo to 20 patients with cluster headache (10 in the active phase and 10 in the remission period) and to 12 controls. The sumatriptan-induced increase of growth hormone concentrations was significantly (P < 0.05) blunted in patients with active cluster headache. Prolactin and ACTH responses to the drug were significantly (P < 0.05) reduced in patients with cluster headache, both in the active and in the remission period. Our results suggest that cerebral serotonergic functions mediated by 5-HT(1D) receptors are altered in patients with episodic cluster headache.

Adult↗
PubMed2003

Differential diagnosis of headache in a neurological department.

Headache is one of the most common symptoms patients attending a neurological department present. Although the overwhelming majority of these headaches are benign and self-limited, headache can be the initial symptom of life-threatening disorders. It is important for physicians to differentiate primary from symptomatic headaches. There are 3 types of primary headaches: migraine, tension-type headache, cluster headache. Symptomatic headaches are numerous and in most cases are not the consequence of serious diseases, however a tumour or a different cerebral disease can be taken into account. Accurate anamnesis and accurate physical examination will help in diagnosing the aetiology of headache. In most cases, neurological and physical exams are normal. Anamnesis is therefore the key to a correct diagnosis.

Brain Neoplasms↗
PubMed2002

Antidisialosyl antibodies in chronic idiopathic ataxic neuropathy.

Antidisialosyl antibodies were found in two out of 13 patients with chronic idiopathic ataxic neuropathy (CIAN) and not in 32 patients with different sensory neuropathies of known cause. This finding confirms the association of antidisialosyl antibodies and CIAN regardless of the absence of the M band. These antibodies may have pathogenic relevance; however, larger series are needed to establish their clinical significance.

Aged↗
PubMed2002

Decreased sensitivity of 5-HT1D receptors in chronic tension-type headache.

OBJECTIVE: To assess the sensitivity of 5-HT1D receptors in chronic tension-type headache using sumatriptan as a pharmacological probe. BACKGROUND: Previous studies have suggested involvement of serotonergic systems in chronic tension-type headache (CTTH), but relevant experimental data are limited. Sumatriptan, a 5-HT1B/1D receptor agonist, stimulates the release of growth hormone (GH) and inhibits the release of ACTH, cortisol, and prolactin. These effects may be used to explore the function of serotonergic systems in vivo. METHODS: We measured GH, ACTH, cortisol and prolactin (PRL) plasma concentrations in 15 patients with chronic tension-type headache and in 18 healthy controls after subcutaneous administration of sumatriptan (6 mg) or placebo. RESULTS: Placebo administration had no effect on hormone concentrations. GH and PRL secretion after sumatriptan administration was significantly (P<0.01 and <0.05) altered in CTTH patients in comparison with controls. CONCLUSION: Our results suggest that cerebral serotonergic functions mediated by 5-HT1D receptors are altered in CTTH.

Adult↗
PubMed2001

Cal-B-catalyzed alkoxycarbonylation of a-ring stereoisomeric synthons of 1alpha,25-dihydroxyvitamin D3 and 1alpha,25-dihydroxy-19-nor-previtamin D3: a comparative study. first regioselective chemoenzymatic synthesis of 19-nor-A-ring carbonates.

A comparative study of alkoxycarbonylation processes of both 19-nor-A-ring and A-ring stereoisomers of 1alpha,25-dihydroxyvitamin D3 analogues catalyzed by Candida antarctica lipase B (CAL-B) has been described. The presence of the methyl group in the A-ring at C-2, as in 3-6, has a determining role in the regioselectivity of the biocatalysis, mainly allowing the hydroxyl group at C-5 position to react. For the 19-nor-A-ring stereoisomers 7-10, which lack the C-2 methyl group, the configurations at C-3 and C-5 have a high influence in the selectivity exhibited by CAL-B. Thus, each couple of enantiomers showed opposing regioselectivities depending on the C-3 configuration. When C-3 possesses an (S)-configuration, enzymatic alkoxycarbonylations took place at the C-5-(R) or C-5-(S) hydroxyl groups. However, if the chiral centers at C-3 are (R), CAL-B alkoxycarbonylated the C-3-(R) hydroxyl group independently of the configuration at C-5. The corresponding carbonates are useful A-ring precursors of 1alpha,25-dihydroxyvitamin D3 analogues, selectively modified at the C-1 or C-3 positions. In addition, an improved synthesis of cis A-ring synthons 5 and 6 is described using a Mitsunobu methodology.

Calcitriol↗
PubMed2001

DNA fingerprint comparison of rainbow trout and RTG-2 cell line using random amplified polymorphic DNA.

The detection of genotoxic effects using in vitro cell systems can be extremely useful in risk assessment procedures. However, care should be taken in the extrapolation of in vitro results since, amongst other factors, established cell lines may deviate from the genetic characteristics of their species. In this work, the genetic similarities between the RTG-2 cell line and rainbow trout individuals (Oncorhynchus mykiss) from several fish farms have been studied by the RAPD technique. Results show a significant analogy in the band patterns obtained for both systems, up to 73% of the bands composing the fingerprint of the RTG-2 cell line were found in all the individuals analysed. The inter-population similarity index (Lynch, 1990), considering the RTG-2 cell line as a population, gives a value of 0.931 between both systems. The dendrogram constructed from all the individuals, considering the RTG-2 cell line as just another individual of a single population, showed that the genetic structure of the cell line was not different from those of the other individuals tested. The strong genetic similarity of both systems, together with the previously proven capability of the RAPD technique to detect genetic alterations caused in vitro by genotoxic agents, can be very useful in genetic ecotoxicological studies.

Animals↗
PubMed2000

6-s-cis locked analogues of the steroid hormone 1alpha, 25-dihydroxyvitamin D(3). Synthesis Of novel A-ring stereoisomeric 1, 25-dihydroxy-3-epi-19-nor-previtamin D(3) derivatives.

Efficient syntheses of A-ring synthons 24 and 32 are described from hydroxy ester 16, which is easily available on a preparative scale from (-)-quinic acid. Key features of the syntheses were (a) the ability to selectively perform desilylations in the presence of p-nitrobenzoate esters and (b) the excellent yield and complete stereospecificity with which the configuration of alcohols 16, 18, and 26 could be inverted under Mitsunobu conditions. Thus, A-ring synthons 24 and 32 were both prepared in 35-38% yield (eight steps) from the common precursor 16. The coupling of A-ring synthons 24 and 32 with the appropriate CD-ring/side chain fragment 7 provides access to novel 6-s-cis locked analogues of steroid hormone 1alpha, 25-dihydroxyvitamin D(3): 1alpha, 25-dihydroxy-3-epi-19-nor-previtamin D(3) (37) and 1beta, 25-dihydroxy-3-epi-19-nor-previtamin D(3) (38), which are unable to undergo rearrangement to the respective vitamin D form by virtue of the absence of the C-19 methyl group. Compounds 37 and 38 can be used as tools for studying the genomic and nongenomic mechanisms of action of the previtamin form of the hormone 1alpha, 25-dihydroxyvitamin D(3).

Calcitriol↗
PubMed2000

Factors affecting the variation in antibiotic resistance of Helicobacter pylori over a 3-year period.

Strains of Helicobacter pylori, isolated from 300 patients between 1996 and 2000 were tested for their sensitivity to clarithromycin, metronidazole and amoxycillin. Primary resistances (95% CI) were 9. 7% for clarithromycin and 21.7% for metronidazole. No strains were resistant to amoxycillin. There was no significant difference between the number of resistant strains in the male and female groups. Clarithromycin resistance was more common in older patients (P<0.01) and metronidazole resistance was more common in patients with peptic ulcer compared with patients with chronic gastritis (P<0. 05). Logistic regression analysis confirmed these results.

Adolescent↗
PubMed2000

Third line treatment for Helicobacter pylori: a prospective, culture-guided study in peptic ulcer patients.

BACKGROUND: A third line treatment is needed in roughly 5% of patients infected with Helicobacter pylori. Few data have been reported on efficacy of treatment regimens in these patients. METHODS: A prospective trial was designed to study the effectiveness of third line treatment of H. pylori infection in ulcer patients. Two-week quadruple, culture-guided, combinations were used in 31 consecutive patients. Susceptibility to metronidazole and clarithromycin were studied by E-test, and thereafter a predetermined treatment regimen was used. Compliance was evaluated by pill count, and eradication defined by negative urea breath test at 6 weeks. RESULTS: Two main quadruple regimens were used in 29 patients. In spite of good compliance, the combination of omeprazole, tetracycline, bismuth and clarithromycin (OTBC) showed an eradication rate (per protocol analysis) of 36% (five out of 14; CI: 12.8-64.9), and if amoxycillin was used (OTBA) the rate was 67% (eight out of 12; CI: 34.9-90.1). The difference was not significant. No clinical factor was found to be associated with failure to eradicate. CONCLUSIONS: Third line treatment often fails to eradicate H. pylori infection. New strategies need to be developed and tested for this common clinical situation.

Adult↗