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Biomedical subjects

G Ferrari

Publications and source records attributed to G Ferrari.

At least 19 recordsLinked to original sources
PubMed2003

Mutations of ANT1, Twinkle, and POLG1 in sporadic progressive external ophthalmoplegia (PEO).

To verify the impact of mutations in ANT1, Twinkle, and POLG1 genes in sporadic progressive external ophthalmoplegia associated with multiple mitochondrial DNA (mtDNA) deletions, DNA samples from 15 Italian and 12 British patients were screened. Mutations in ANT1 were found in one patient, in Twinkle in two patients, and in POLG1 in seven patients. Irrespective of the inheritance mode, screening of these genes should be performed in all patients with progressive external ophthalmoplegia with multiple mtDNA deletions.

Adenine Nucleotide Translocator 1↗
PubMed2003

Mirtazapine in the treatment of panic disorder: an open-label trial.

The aim of this open label trial was to evaluate mirtazapine tolerability and effectiveness in controlling symptomatology of patients with panic disorder. Forty-five patients with panic disorder, with or without agoraphobia, 11 of them with a comorbid diagnosis of major depression, were included. Patients were assessed with a structured psychiatric interview and their symptomatology evaluated with specific psychometric scales. Three study participants dropped out due to adverse events. Mirtazapine was administered at an established dose of 30 mg daily for 3 months. Patients were assessed at weeks 2 and 4, and then at monthly intervals. All psychometric measures showed statistically significant reductions in total scores at the rated time points, with a pronounced decline in number and intensity of panic attacks and anticipatory anxiety throughout the study. Mirtazapine was well tolerated as signified by the low discontinuation rate (6.3%), and all patients showed a significant symptomatic improvement. The improvement did not appear to be linked to the concurrent presence of a depressive illness.

Adult↗
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↗
PubMed2003

A hybrid mock circulatory system: development and testing of an electro-hydraulic impedance simulator.

Mock circulatory systems are used to test mechanical assist devices and for training and research purposes; when compared to numerical models, however, they are not flexible enough and rather expensive. The concept of merging numerical and physical models, resulting in a hybrid one, is applied here to represent the input impedance of the systemic arterial tree, by a conventional windkessel model built out of an electro-hydraulic (E-H) impedance simulator added to a hydraulic section. This model is inserted into an open loop circuit, completed by another hybrid model representing the ventricular function. The E-H impedance simulator is essentially an electrically controlled flow source (a gear pump). Referring to the windkessel model, it is used to simulate the peripheral resistance and the hydraulic compliance, creating the desired input impedance. The data reported describe the characterisation of the E-H impedance simulator and demonstrate its behaviour when it is connected to a hybrid ventricular model. Experiments were performed under different hemodynamic conditions, including the presence of a left ventricular assist device (LVAD).

Computer Simulation↗
PubMed2002

Collisional properties of ultracold K-Rb mixtures.

We determine the interspecies s-wave triplet scattering length a(3) for all K-Rb isotopic mixtures by measuring the elastic cross section for collisions between 41K and 87Rb in different temperature regimes. The positive value a(3)=+163(+57)(-12)a(0) ensures the stability against collapse of binary (41)K- (87)Rb Bose-Einstein condensates. For the fermion-boson mixture (40)K- (87)Rb, we obtain a large and negative scattering length which implies an efficient sympathetic cooling of the fermionic species down to the degenerate regime.

Journal Article↗
PubMed2002

Formation of a matter-wave bright soliton.

We report the production of matter-wave solitons in an ultracold lithium-7 gas. The effective interaction between atoms in a Bose-Einstein condensate is tuned with a Feshbach resonance from repulsive to attractive before release in a one-dimensional optical waveguide. Propagation of the soliton without dispersion over a macroscopic distance of 1.1 millimeter is observed. A simple theoretical model explains the stability region of the soliton. These matter-wave solitons open possibilities for future applications in coherent atom optics, atom interferometry, and atom transport.

Journal Article↗
PubMed2002

The non-immunosuppressive immunophilin ligand GPI-1046 potently stimulates regenerating axon growth from adult mouse dorsal root ganglia cultured in Matrigel.

We used explant cultures of adult mouse dorsal root ganglia with spinal nerve attached growing in Matrigel to assess the effects of the non-immunosuppressive immunophilin ligand GPI-1046 [Snyder et al. (1998) TIPS 19, 21-26] on the growth rate of regenerating sensory axons and found a potent stimulation of axon growth. In these explant cultures, naked, unfasciculated axons emerge from the cut end of the spinal nerve and continue to grow in the Matrigel for up to eight days [Tonge et al. (1996) Neuroscience 73, 541-551]. Some axons are entirely smooth whilst others show prominent varicosities. Some of the former express the phosphorylated neurofilament epitope recognised by monoclonal antibody RT97, a marker for large calibre, myelinated axons, whilst the latter express calcitonin gene-related peptide, predominantly a marker for unmyelinated, and small diameter myelinated sensory axons. Many of the axons in these cultures also express the low-affinity neurotrophin receptor p75. GPI-1046 has been shown to have striking stimulatory effects on embryonic primary sensory axons growing in vitro and it was therefore of interest to see whether it could also enhance regenerating sensory axon growth from the adult ganglia in our cultures. GPI-1046 potently stimulated axon growth in our cultures in a dose-dependent manner. The stimulatory effect was not dependent on the class of sensory axon. These observations show that GPI-1046 is a potent stimulator of regenerating axons from adult, primary sensory neurones. The cellular site of action of GPI-1046 is unknown. To distinguish between a direct effect of the drug on neurones and an indirect effect we compared the effects of GPI-1046 on explant and dissociated cultures. In confirmation of previous results, we found that GPI-1046 potently stimulated axon outgrowth from explants of embryonic chick dorsal root ganglia. However, the drug was without effect on dissociated embryonic dorsal root ganglion neurones, suggesting that non-neuronal cells are important for axon growth stimulation.

Animals↗
PubMed2002

Study of systolic pressure variation (SPV) in presence of mechanical ventilation.

Systolic pressure variation (SPV) and its components (dUp and dDown) have been demonstrated to be of interest in assessing preload in mechanically ventilated patients. The aim of this paper is to analyse the sensitivity of these variables to preload and volemic changes during mechanical ventilation in different conditions of the cardiovascular system. Computer simulation experiments have been done using a modular lumped parameter model of the cardiovascular system. The effect of mechanical ventilation has been reproduced operating on intrathoracic pressure. Experiments have been performed varying preload through filling pressure. Sensitivity of SVP dUp and dDown is described varying separately left ventricular elastance (Ev), systemic arterial resistance (Ras) and systemic arterial compliance (Cas). The sensitivity of SPV and dDown to preload and filling pressure is appreciable for high values of Ev and for a wide variation of Ras. Preliminary clinical data concerning the three parameters show good correlation with simulation results.

Blood Pressure↗
PubMed2002

Surface characterization and debris analysis of ceramic pairings after ten million cycles on a hip joint simulator.

This study was aimed at characterizing the ceramic wear particles produced during tests on a hip joint wear simulator of up to 10 million cycles. Alumina and alumina-zirconia composites were studied as commercial or potential hip joint products respectively. No ceramic particles could be observed, even after a careful isolation procedure. This confirms the low wear rate found for these materials in previous works (of the order of tenths of milligrams per million cycles). Surface characterization was conducted by means of scanning electron microscopy. It confirms the low wear regime of ceramic pairings and allows ceramic wear debris morphology to be defined. The effect of microstructure on surface wear is discussed.

Aluminum Oxide↗
PubMed2001

Preoperative localization of indeterminate pulmonary nodules before videothoracoscopic resection.

BACKGROUND: The management of a solitary pulmonary nodule is the subject of debate and minimally invasive diagnostic approaches have low sensitivity for small peripheral nodules. We discuss the role of video-assisted thoracoscopic surgery (VATS) in the management of solitary pulmonary nodules (SPNs) < or = 1 cm performed with a preoperative computed tomography-guided wire localization. METHODS: Thirty-five selected patients underwent VATS resection for SPN, with localization by guide wire before surgery. RESULTS: Seven patients, after VATS exploration, underwent thoracotomy because of pleuropulmonary adhesions, depth or dimensions. Histological diagnosis was obtained in all procedures; there was no postoperative morbidity or morbidity. CONCLUSION: Preoperative computed tomography hook-wire localization is a suitable strategy for peripheral nodules < or = 1 cm in diameter.

Humans↗
PubMed2001

CD8 CTL responses in vaccines: emerging patterns of HLA restriction and epitope recognition.

We evaluated MHC-class I-restricted CTL responses induced by HIV-1 clade B-based vaccines in nine HIV-1 seronegative vaccine recipients with regard to their patterns of HLA restriction and epitope recognition. We found that seven of nine volunteers developed detectable CTL reactivities against novel epitopes within the HIV-1 Env and Gag proteins. Although four of nine subjects were HLA-A*0201, none of the cellular responses was restricted in the context of this allele. The type of responses observed in this sampling of vaccines appeared similar to those reported during primary infection and among long term non-progressors, with three out of nine subjects recognizing HLA-B27 or HLA-B17(57)-restricted epitopes. Although the majority of CTL responses were directed against novel epitopes, these effectors were still able to mediate cross-clade reactivities.

AIDS Vaccines↗
PubMed2001

Bose-Einstein condensation of potassium atoms by sympathetic cooling.

We report on the Bose-Einstein condensation of potassium atoms, whereby quantum degeneracy is achieved by sympathetic cooling with evaporatively cooled rubidium. Because of the rapid thermalization of the two different atoms, the efficiency of the cooling process is high. The ability to achieve condensation by sympathetic cooling with a different species may provide a route to the production of degenerate systems with a larger choice of components.

Journal Article↗
PubMed2001

Collapsin response mediator protein switches RhoA and Rac1 morphology in N1E-115 neuroblastoma cells and is regulated by Rho kinase.

The formation and directional guidance of neurites involves dynamic regulation of Rho family GTPases. Rac and Cdc42 promote neurite outgrowth, whereas Rho activation causes neurite retraction. Here we describe a role for collapsin response mediator protein (Crmp-2), a neuronal protein implicated in axonal outgrowth and a component of the semaphorin 3A pathway, in switching GTPase signaling when expressed in combination with either dominant active Rac or Rho. In neuroblastoma N1E-115 cells, co-expression of Crmp-2 with dominant active RhoA V14 induced Rac morphology, cell spreading and ruffling (and the formation of neurites). Conversely, co-expression of Crmp-2 with dominant active Rac1 V12 inhibited Rac morphology, and in cells already expressing Rac1 V12, Crmp-2 caused localized peripheral collapse, involving Rho (and Cdc42) activation. Rho kinase was a pivotal regulator of Crmp-2; Crmp-2 phosphorylation was required for Crmp-2/Rac1 V12 inhibition, but not Crmp-2/RhoA V14 induction, of Rac morphology. Thus Crmp-2, regulated by Rho kinase, promotes outgrowth and collapse in response to active Rho and Rac, respectively, reversing their usual morphological effects and providing a mechanism for dynamic modulation of growth cone guidance.

3T3 Cells↗
PubMed2001

Quasipure Bose-Einstein condensate immersed in a Fermi sea.

We report the observation of coexisting Bose-Einstein condensate (BEC) and Fermi gas in a magnetic trap. With a very small fraction of thermal atoms, the 7Li condensate is quasipure and in thermal contact with a 6Li Fermi gas. The lowest common temperature is 0.28 microK approximately 0.2(1)T(C) = 0.2(1)T(F) where T(C) is the BEC critical temperature and T(F) the Fermi temperature. The 7Li condensate has a one-dimensional character.

Journal Article↗
PubMed2001

alpha2-chimaerin, a Cdc42/Rac1 regulator, is selectively expressed in the rat embryonic nervous system and is involved in neuritogenesis in N1E-115 neuroblastoma cells.

Neuronal differentiation involves Rac and Cdc42 GTPases. alpha-Chimaerin, a Rac/Cdc42 regulator, occurs as alpha1- and alternatively spliced Src homology 2 (SH2) domain-containing alpha2-isoforms. alpha2-chimaerin mRNA was highly expressed in the rat embryonic nervous system, especially in early postmitotic neurons. alpha1-chimaerin mRNA was undetectable before embryonic day 16.5. Adult alpha2-chimaerin mRNA was restricted to neurons within specific brain regions, with highest expression in the entorhinal cortex. alpha2-chimaerin protein localized to neuronal perikarya, dendrites, and axons. The overall pattern of alpha2-chimaerin mRNA expression resembles that of cyclin-dependent kinase regulator p35 (CDK5/p35) which participates in neuronal differentiation and with which chimaerin interacts. To determine whether alpha2-chimaerin may have a role in neuronal differentiation and the relevance of the SH2 domain, the morphological effects of both chimaerin isoforms were investigated in N1E-115 neuroblastoma cells. When plated on poly-lysine, transient alpha2-chimaerin but not alpha1-chimaerin transfectants formed neurites. Permanent alpha2-chimaerin transfectants generated neurites whether or not they were stimulated by serum starvation, and many cells were enlarged. Permanent alpha1-chimaerin transfectants displayed numerous microspikes and contained F-actin clusters, a Cdc42-phenotype, but generated few neurites. In neuroblastoma cells, alpha2-chimaerin was predominantly soluble with some being membrane-associated, whereas alpha1-chimaerin was absent from the cytosol, being membrane- and cytoskeleton-associated, paralleling their subcellular distribution in brain. Transient transfection with alpha2-chimaerin mutated in the SH2 domain (N94H) generated an alpha1-chimaerin-like phenotype, protein partitioned in the particulate fraction, and in NGF-stimulated pheochromocytoma cell line 12 (PC12) cells, neurite formation was inhibited. These results indicate a role for alpha2-chimaerin in morphological differentiation for which its SH2 domain is vital.

Aging↗
PubMed2001

Acute and mid-term results of phosphorylcholine-coated stents in primary coronary stenting for acute myocardial infarction.

The aim of this pilot study was to evaluate the safety and efficacy of the BiodivYsio phosphorylcholine-coated stent in the primary treatment of acute myocardial infarction. The BiodivYsio stent (Biocompatible) is a balloon-expandable stent, laser etched from a 316 L stainless steel tube. This device is coated with phosphorylcholine, a synthetic, hemocompatible phospholipid polymer that has been shown in experimental studies to reduce platelet and protein adhesion to the surface of the metal. One hundred consecutive patients within 24 hr of symptoms of onset of acute MI, treated with primary PTCA, were enrolled. After PTCA, stenting was attempted in all eligible lesions (reference diameter > or = 2.5 mm; no bend lesion > 45 degrees ). Poststenting regimens contained ticlopidine (500 mg/day) and aspirin (325 mg/day) and 6-12 hr of heparin infusion. Procedural success (TIMI > or = II and residual stenosis < 30%) was obtained in 70/74 cases (95%). TIMI grade III was restored in 90% of cases. In the patient group with procedural success (70 cases), 70 BiodivYsio stents were placed. After stenting, diameter stenosis decreased from 96% +/- 11% to 22% +/- 12% (P < 0.01) and minimal luminal diameter increased from 0.13 +/- 0.29 to 2.47 +/- 0.43 (P < 0.01). Nominal stent diameter was between 3.0 and 4.0 mm (mean, 3.5 +/- 0.4 mm). Stent length was between 11 and 28 mm (mean, 17 +/- 4.5 mm). Clinical follow-up was obtained in all patients; angiographic follow-up was performed in 65/70 (93%). No acute or subacute thrombosis was reported. Two in-hospital major adverse cardiac events (MACE) were reported due to a nontreated left main disease that required coronary artery bypass graft (CABG) surgery. At follow-up, MACE were found in 9 of 68 patients (13%), target lesion revascularization (TLR) in 6%, and CABG in the remaining 6%. Primary stenting with phosphorylcholine-coated stent leads to excellent short- and mid-term clinical outcomes and is associated with a restenosis rate of 12%.

Aged↗