Biomedical subjects

C Bianchi

Publications and source records attributed to C Bianchi.

At least 19 recordsLinked to original sources

PubMed2006

Serotonin modulation of cell excitability and of [3H]GABA and [3H]D-aspartate efflux in primary cultures of rat cortical neurons.

The effects of 5-hydroxytryptamine (5-HT) on neuronal excitability, evaluated as depolarization-induced firing rate, and on amino acid release, measured as electrically-evoked [(3)H]GABA and [(3)H]d-aspartate efflux, were investigated in rat primary cortical neuronal cultures. 5-HT displayed a concentration-dependent, bimodal effect on neuronal excitability: at 3-10microM it increased excitability through 5-HT(2A) receptors, and was blocked by the selective 5-HT(2A) antagonist MDL 100907, whereas at 30-100microM it reduced excitability through 5-HT(1A) receptors, and was, in turn, blocked by the selective 5-HT(1A) antagonist WAY 100135. The electrically-evoked [(3)H]GABA efflux was concentration-dependently inhibited by 5-HT (pEC(50)=4.74) and such inhibition was prevented by WAY 100135, but not by GR 55562, a selective 5-HT(1D/B) receptor antagonist. Conversely, 5-HT concentration-dependently increased stimulus-evoked [(3)H]d-aspartate efflux (pEC(50)=4.71). The increase was facilitated by methiothepin and was reversed into inhibition by ICS 205930, a selective 5-HT(3) receptor antagonist. In the presence of ICS 205930, the inhibition induced by 5-HT was prevented by the selective 5-HT(1D/B) receptor antagonist GR 55562, but not by WAY 100135. These findings suggest that 5-HT inhibits GABA release through 5-HT(1A) receptors and exerts a dual modulation on glutamate release, mostly facilitatory (through 5-HT(3) receptors) but also inhibitory (through 5-HT(1D/B) receptors), leading to a prevalently positive modulation of the excitatory signal by amino acid neurotransmitter containing neurons.

Animals↗

PubMed2006

Long-term functional outcome measures in corticosteroid-treated complex regional pain syndrome.

AIM: The aim of this paper was to assess the effects of low-dose systemic corticosteroid therapy in complex regional pain syndrome (CRPS), to measure the long-term functional outcome, and to evaluate an arbitrary scale of severity of CRPS. METHODS: An evaluation of 31 consecutive subjects diagnosed with CRPS before and after they underwent corticosteroid therapy was carried out. The clinical and functional variables considered were evaluated at baseline, halfway through therapy, at the end and after 1, 6 and 12 months after the end of treatment. A clinical severity scale of CRPS was devised. RESULTS: The comparison between baseline and post-treatment data of the principal variables resulted in all cases significant (P<0.001), as did, in most cases, the changes in variables between successive time intervals (P<0.05), supporting the long-term efficacy of treatment. The score of the clinical severity scale of CRPS showed a significant improvement in the one-year follow-up. CONCLUSION: Corticosteroid therapy in CRPS provides a short-term response to the pain with a low risk of side effects. The improvement in all the variables considered persisted at one-year follow-up. The arbitrary scale of clinical severity of CRPS should be further tested in order to propose it as an instrument for use in following the course of CRPS.

Adrenal Cortex Hormones↗

PubMed2005

Effects of chemical ischemia in cerebral cortex slices. Focus on nitric oxide.

Superfused rat cerebral cortex slices were submitted to a continuous electrical (5 Hz) stimulation and treated with sodium azide (1-10 mM) in the presence of 2 mM 2-deoxyglucose ("chemical ischemia"). Presynaptic cholinergic activity, evaluated as acetylcholine release, was inhibited depending on the sodium azide concentrations and on the length of application (5-30 min). Following a 5-min treatment with 10 mM sodium azide, acetylcholine release was reduced to 45+/-2.3%; simultaneously, there was a 15- and 10-fold increase in glutamate and nitric oxide effluxes, respectively. After restoring normal superfusion conditions, acetylcholine release recovered to 70+/-3.1% of the controls; the N-methyl-D-aspartate receptor antagonist MK-801 (10 microM) as well as the nitric oxide scavengers, haemoglobin (20 microM) and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide (150 microM), improved the recovery in presynaptic activity, showing that both glutamate and nitric oxide play detrimental roles in chemical ischemia. On the other hand, the post-ischemic recovery was worsened by the guanylylcyclase inhibitor 1H-[l,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (10 microM), suggesting that the activation of such a pathway plays a neuroprotective role and that the nitric oxide-induced harmful effects depend on different mechanisms. Chemical ischemia-evoked nitric oxide efflux partly derived from its calcium-dependent endogenous synthesis, since both the intracellular calcium chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (1 mM), and the nitric oxide synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (100 microM), substantially prevented sodium azide effects. Nitric oxide efflux was only weakly reduced by MK-801 and was not modified by either the L-type calcium channel blocker, nifedipine (10 microM) or the N-type calcium channel blocker omega-conotoxin (0.5 microM), thus suggesting a prevailing intracellular calcium-dependence of nitric oxide production, although a partial extracellular calcium source cannot be ruled out. These findings show that sodium azide plus 2-deoxyglucose treatment is a useful protocol to induce brain ischemia in vitro and underline the involvement of nitric oxide in the complex events following the ischemic insult.

Acetylcholine↗

PubMed2005

Clinical and socio-economic impact of influenza and respiratory syncytial virus infection on healthy children and their households.

This prospective study compared the clinical and socio-economic impact of laboratory-confirmed influenza and respiratory syncytial virus (RSV) infection on healthy children and their families. Among 1,520 otherwise healthy children aged< 15 years attending the Emergency Department for acute conditions other than trauma, influenza viruses and RSV were found in 234 (15.4%) and 116 (7.6%; p<0.0001) patients, respectively. The fact that influenza has a similar global clinical impact on the community to that of RSV infection, but represents a greater socio-economic burden, may contribute to broadening the acceptance of influenza vaccination.

Child↗

PubMed2005

[Topographic anatomy of the asterion].

BACKGROUND: In the surgical approaches to the posterior fossa, the accurate location of the transverse-sigmoid sinus (TS-SS) complex is of great importance. The asterion is a referral landmark to the transverse sinus location. METHOD: Twenty-five skulls of adult cadavers were studied. We seek for the relationships of the asterion with: TS location, mastoid emissary vein, suprametal crest and inion. RESULTS: The asterion was found in 49 cases. In the great majority of cases (87.8%) the asterion was over the TS (72.2% over the sinus proper, 27.8% over the TS-SS transition). The mastoid emissary vein was present in 46 cases, and in 36% we found two veins. DISCUSSION AND CONCLUSIONS: The burr hole for posterolateral approaches to the posterior fossa must be located below and behind the asterion.

Adult↗

PubMed2004

Radiochromic film measurement of anisotropy function for high-dose-rate Ir-192 brachytherapy source.

The dose distribution produced by the high-dose-rate (HDR) 192Ir source is inherently anisotropic due to self-absorption by the high-density source core, oblique filtration by the source capsule and the asymmetric geometry of the source capsule. To account for the dose distribution anisotropy of brachytherapy sources, AAPM Task Group No 43 has included a two-dimensional anisotropy function, F(r, theta), in the recommended dose calculation formalism. Gafchromic HS radiochromic film (RCF) was used to measure anisotropy function for microSelectron HDR 192Ir source (classic/old design). Measurements were carried out in a water phantom using specially fabricated PMMA cylinders at radial distances 1, 2, 3, 4 and 5 cm. The data so generated are comparable to both experimental and Monte Carlo calculated values for this source reported earlier by other authors. The RCF method described in this paper is comparatively high resolution, simple to use and is a general method, which can be applied for other brachytherapy sources as well.

Algorithms↗

PubMed2004

Intestinal perforation as a long-term complication of plug and mesh inguinal hernioplasty: case report.

Tension-free and sutureless hernioplasty by plug and mesh of nonreabsorbable material is one of the most common techniques for inguinal hernia repair. It's a simple and quick procedure with a low cost and allows for a short hospital stay. It shows a low reoccurrence rate, but it can result, in very few cases, in complications strictly related to prosthetic material. The literature describes some cases of plug migration from its proper position, for example, to the scrotum, preperitoneal adipose tissue, and abdominal cavity. We report on a case of sigmoid colon perforation due to a plug of Trabucco hernioplasty performed 2 years previously.

Aged↗

PubMed2004

Effects of nociceptin/orphanin FQ and endomorphin-1 on glutamate and GABA release, intracellular [Ca2+] and cell excitability in primary cultures of rat cortical neurons.

The effects of nociceptin/orphanin FQ (N/OFQ) and endomorphin-1 (EM-1) on glutamate and GABA release, intracellular calcium, neuronal excitability and glutamate current were investigated in rat primary cortical neuronal cultures. Through their specific receptors N/OFQ and EM-1 (0.02-1 microM) inhibited the electrically evoked outflow of [3H]D-aspartate at most to -50% and that of [3H]GABA to -30%. In addition, at 1 microM, both peptides induced a decrease of the firing rate caused by electrical depolarization. N/OFQ 1-10 microM did not influence either the electrically evoked calcium influx or the glutamate-evoked currents, whereas EM-1 1 microM significantly inhibited them. Thus, in cortical neurons in culture, both N/OFQ and EM-1 inhibited the secretory process and neuronal excitability but EM-1 also affected calcium influx and cell body responsiveness to glutamate. Consequently, EM-1 appeared to dampen this excitatory signal more then N/OFQ did.

Action Potentials↗

PubMed2004

Efficacy of glossopharyngeal breathing for a ventilator-dependent, high-level tetraplegic patient after cervical cord tumor resection and tracheotomy.

This case study was undertaken to describe the use and limitations of glossopharyngeal breathing (GPB) by a ventilator-dependent, tracheotomized patient after cervical tumor resection. A 6-yr, 8-mo-old, tracheotomized, ventilator-dependent boy, after cervical tumor resection, learned GPB on his own and used it for ventilator-free breathing. Over the next 16 yrs, his GPB efficacy improved to the point that, with a vital capacity of 670 ml, his GPB maximum single-breath capacity increased to 3300 ml. This was limited by the fact that at 2.9 l of lung volume, air began to leak around the tracheostomy tube walls and out of the stoma. Still, GPB permitted up to 12 hrs/day of ventilator-free breathing. Measurements of assisted peak cough flow and GPB lung insufflations exceeding vital capacity are the main measures that demonstrate adequate tube fit to permit effective GPB in the presence of an indwelling tracheostomy tube.

Adult↗

PubMed2003

Control of respiration by nitric oxide in Keilin-Hartree particles, mitochondria and SH-SY5Y neuroblastoma cells.

The pattern of cytochrome c oxidase inhibition by nitric oxide (NO) was investigated polarographically using Keilin-Hartree particles, mitochondria and human neuroblastoma cells. NO reacts with purified cytochrome c oxidase forming either a nitrosyl- or a nitrite-inhibited derivative, displaying distinct kinetics and light sensitivity of respiration recovery in the absence of free NO. Keilin-Hartree particles or cells, respiring either on endogenous substrates alone or in the presence of ascorbate, as well as state 3 and state 4 mitochondria respiring on glutamate and malate, displayed the rapid recovery characteristic of the nitrite derivative. All systems, when respiring in the presence of tetramethyl-p-phenylenediamine, were characterised by the slower, light-sensitive recovery typical of the nitrosyl derivative. Together the results suggest that the reaction of NO with cytochrome c oxidase in situ follows two alternative inhibition pathways, depending on the electron flux through the respiratory chain.

Animals↗

PubMed2003

Hyperglycaemia and cardiovascular risk.

Cardiovascular diseases represent, today, the principal cause of mortality in the general population, especially in subjects with type 2 diabetes mellitus. In these patients the risk of death from cardiovascular diseases is equal to that of non-diabetic subjects with a previous episode of myocardial infarction. Many factors concur to determine such high risk. Hyperglycaemia contributes to the increase in morbidity and cardiovascular mortality associated with diabetes mellitus. Hyperglycaemia acts as a multiplier of cardiovascular risk due to frequent association of multiple risk factors in diabetic patients. Therefore, effective treatment requires a more complete assessment of quantitative and qualitative aspects of glycemic control as well as all components of the diabetic syndrome or, more commonly, metabolic syndrome.

Biomarkers↗

PubMed2003

Use of antiparkinsonian drugs in the Umbria Region.

Discussion of differences between recommended guidelines and clinical practice is very useful in medicine. The use of a computerized database of all prescriptions of antiparkinsonian drugs enabled us to perform an epidemiological population-based study with low cost and in a relatively short time. We have identified 2 827 parkinsonian patients in November 2000 and estimate the number of patients taking dopaminoagonists aged >75 years, antidepressive drugs, and atypical neuroleptics.

Aged↗

PubMed2003

Effects of cholecystokinin tetrapeptide (CCK(4)) and of anxiolytic drugs on GABA outflow from the cerebral cortex of freely moving rats.

The effect of cholecystokinin tetrapeptide (CCK(4)) and of different anxiolytic drugs on GABA outflow from the cerebral cortex was investigated in freely moving rats, by using the epidural cup technique. CCK(4) (3-30 microg/kg, i.p.) increased GABA outflow and induced objective signs of anxiety. These neurochemical and behavioral responses were prevented by the CCK(B) antagonist GV150013 at 0.1 microg/kg (i.p.). At higher doses (up to 30 microg/kg) this compound per se reduced GABA release and caused sedation, suggesting the presence of a CCKergic positive tonic modulation on GABA interneurons. Similarly the GABA(A) receptors modulator, diazepam (2mg/kg, i.p.) and the 5-HT(1A) agonist buspirone (3mg/kg, i.p.) reduced GABA outflow and caused the expected behavioral effects (reduced muscle tone, mild 5-HT syndrome) which were prevented by the respective, selective antagonists, flumazenil (1mg/kg, i.p.) and NAN-190 (3mg/kg, i.p.). These findings support the idea that GV150013, diazepam and buspirone inhibit GABAergic cortical activity, through the respective receptors. This neurochemical effect may represent the end-effect of various anxiolytic compounds affecting the cortical circuitry.

Adamantane↗

PubMed2002

Factor V Leiden mutation and patent foramen ovale in ischemic stroke.

We report a 47-years-old male with ischemic stroke, whose arteriographic and echocardiographic investigations did not reveal any steno-occlusive arterial disease or embolic source from the left cardiac chambers. A transesophageal echocardiogram showed a patent foramen ovale (PFO), whilst laboratory screening for coagulation abnormalities showed heterozygosity for factor V Leiden mutation. The significance of the association of PFO with factor V Leiden mutation is discussed as a possible cause of ischemic stroke through paradoxical embolism from a venous source. The high prevalence of these two conditions in the general population is emphasized and the indication for anticoagulant therapy is discussed.

Activated Protein C Resistance↗

PubMed2002

Nociceptin/orphanin FQ receptors modulate glutamate extracellular levels in the substantia nigra pars reticulata. A microdialysis study in the awake freely moving rat.

Intracerebral microdialysis was employed in awake freely moving rats to investigate the effects of nociceptin/orphanin FQ receptor ligands on glutamate extracellular levels in the substantia nigra pars reticulata. Nociceptin/orphanin FQ, ineffective at 0.1 microM, induced a prolonged stimulation of nigral glutamate levels at 1 and 10 microM (mean effect of 137+/-9 and 167+/-13%, respectively, of basal values). These effects were prevented by the novel nociceptin/orphanin FQ receptor antagonist [Nphe(1)]nociceptin/orphanin FQ(1-13)NH(2) (100 and 300 microM, respectively) but not by the non-selective opioid receptor antagonist naloxone (10 microM). [Nphe(1)]nociceptin/orphanin FQ(1-13)NH(2) (100 microM) inhibited by itself glutamate outflow (maximal reduction to 71+/-4%) while naloxone was ineffective. The nociceptin/orphanin FQ receptor ligand [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin/orphanin FQ(1-13)NH(2) also facilitated glutamate outflow at 10 microM (mean effect of 145+/-10%). Intranigral perfusion with tetrodotoxin (1 microM) or with the dopamine D(2) receptor antagonist raclopride (1 microM), failed to affect basal glutamate output and prevented the facilitatory effect of nociceptin/orphanin FQ (10 microM). However, perfusion with the GABA(A) receptor antagonist bicuculline (10 microM) increased local glutamate extracellular levels by itself and attenuated the effect of the peptide. Our data suggest that nociceptin/orphanin FQ increases glutamate extracellular levels in the substantia nigra pars reticulata via activation of nociceptin/orphanin FQ receptors located on non-glutamatergic, possibly dopaminergic and GABAergic, neuronal elements.

Animals↗

PubMed2002

Patient effective dose from endovascular brachytherapy with 192Ir sources.

The growing use of endovascular brachytherapy has been accompanied by the publication of a large number of studies in several fields, but few studies on patient dose have been found in the literature. Moreover, these studies were carried out on the basis of Monte Carlo simulation. The aim of the present study was to estimate the effective dose to the patient undergoing endovascular brachytherapy treatment with 112Ir sources, by means of experimental measurements. Two standard treatments were taken into account: an endovascular brachytherapy of the coronary artery corresponding to the activity x time product of 184 GBq.min and an endovascular brachytherapy of the renal artery (898 GBq.min). Experimental assessment was accomplished by thermoluminescence dosemeters positioned in more than 300 measurement points in a properly adapted Rqndo phantom. A method has been developed to estimate the mean organ doses for all tissues and organs concerned in order to calculate the effective dose associated with intravascular brachytherapy. The normalised organ doses resulting from cronary treatment were 2.4 x 10(-2) mSv.GBq(-1).min(-1) for lung, 0.9 x 10(-2) mSv.GBSq(-1).min(-1) for oesophagus and 0.48 x 10(-2) mS.GBq(-1).min(-1) for bone marrow. During brachytherapy of the renal artery, the corresponding normalised doses were 4.2 x 10(-2) mS.GBq(-1).min(-1) for colon, 7.8 x 10(-2) mSv.GBq(-1).min(-1) for stomach and 1.7 x 10(-2) mSv.GBq(-1).min(-1) for liver. Coronary treatment iJnvlled an efl'fective dose of (0.046 mSv.GBq(-1).min(-1), whereas the treatment of the renal artery resulted in an effective dose of 0.15 mSv.GBq(-1).min(-1); there were many similarities with data from former studies. Based on these results it can be concluded that the dose level of patients exposed during brachytherapy treatment is low.

Arteries↗

PubMed2002

[Ulcero-necrotic and lymphoproliferative naso-paranasal lesions in cocaine abuse].

In this work are reported two clinical cases of cocaine abusers with destructive lesions of nasal-paranasal cavities. The clinical presentation and the absence of a positive history of drug addiction led to a differential diagnosis between lymphoma, idiopathic median line granuloma and Wegener granulomatosis. Biochemical and serological examinations did not prove conclusive. The diagnosis was finally formulated on the basis of the documented presence of cocaine in the biological fluids. Emphasis is placed in the difficulty of obtaining a reliable case history in this type of patients. Moreover, the Authors point out that it is advisable to test for drugs in the biological fluids prior to undertaking time-consuming diagnostic procedures for pathologies which are extremely rare in the West countries.

Adult↗

PubMed2002

A new method to assess the fluidodynamic behaviour of an angiographic contrast agent.

PURPOSE: To propose a new method for the assessment of the fluidodynamic behaviour of angiographic contrast agents. The method enables measurement of the spatial distribution and time dependence of the contrast agent along a pseudo-vessel on images obtained with an X-ray image intensifier. MATERIAL AND METHODS: A particular phantom was devised consisting of a plexiglas box with an insert into which a latex tube with a 0.4 cm in diameter was placed in order to simulate the tortuous flow of a blood vessel. The box, which is filled with water to simulate the thickness of a normal patient, is connected to an injection and pumping system which serve to keep the contrast agent flowing in the pseudo-vessel tube. The pseudo-vessel tube was filled with plain water in one case and with saline solution in another case to assess their different dilution capabilities. The phantom and the flow of contrast agent were imaged with a conventional X-ray image intensifier system and the images were stored in digital format during 35 second acquisitions at a speed of 4 frames per second; for any frame it is possible to measure the mathematical contrast in any position in the image. Further, a diagram showing the time dependence of the spatial distribution of the mathematical contrast is proposed. The X axis shows the spatial distribution of the mathematical contrast, whereas the Y axis shows its temporal variation with a gray level proportional to the mathematical contrast value. By building an horizontal profile of this diagram one can obtain the spatial distribution at a fixed time, while by building a vertical profile one can obtain the temporal variation at a fixed point. Several different contrast agents were so tested. RESULTS: The proposed method allows different fluido-dynamic behaviour patterns of contrast agents and flowing media to be shown. Owing to the different chemical characteristics of water and saline solution these media have different dilution capabilities (higher for water) and this is well demonstrated by the diagram profiles obtained for each. The system has also allowed the detection of a particular behaviour of some contrast agents, whose spatial distribution was non uniform even in the last frames, thus showing a tendency to maintain their bolus-nature over time. An interesting feature which can be noticed in all the temporal profiles is the presence of a "pre-bolus", i.e. the contrast is higher at the very beginning of the flow, then decreases and after some time starts to increase again. Though the initial contrast value obviously depends on the iodine concentration employed, the method shows the contrast variation as a function of time is different for different contrast agents. CONCLUSIONS: The method and the equipment proposed provide a good description of the fluidodynamic behaviour of different contrast agents, but do not constitute a reference method for testing haemodynamic behaviour which, "in vivo", is obviously affected by several other chemical and metabolic factors. However, the method allows evaluation of the contrast agents from a physical and fluidodynamic point of view, showing that the iodine content is not the only feature affecting their behaviour. The method can be used in quality control to test the constancy of the physical behaviour of different contrast agents.

Angiography↗