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Biomedical subjects

E Donati

Publications and source records attributed to E Donati.

At least 19 recordsLinked to original sources
PubMed2002

Determination of losartan and hydrochlorothiazide in tablets by CE and CEC.

Capillary Electrophoresis (CE) and Capillary Electrochromatography (CEC) have been used to determine losartan and hydrochlorothiazide. The CE separation was carried out in an uncoated capillary filled with a 100 mM sodium borate pH 9 solution containing trimethyl-beta-cyclodextrins. CEC was performed using a capillary packed with a RP-18 stationary phase. The mobile phase was a mixture of 50 mM ammonium acetate pH 7, water, acetonitrile (1/1.5/7.5). By CE and CEC suitable methods to determine simultaneously losartan and hydrochlorothiazide in working standard mixture or pharmaceutical form were obtained. The proposed methods are very simple and both gave accurate and precise results.

Antihypertensive Agents↗
PubMed2002

Chiral discrimination by HPLC and CE and antifungal activity of racemic fenticonazole and its enantiomers.

Fenticonazole is a chiral antifungal agent, used in therapy as the racemic mixture. The investigation on the chirality of fenticonazole is reported in this study. rac-Fenticonazole was resolved by HPLC and by capillary electrophoresis (CE). The chiral stationary phase (CSP), used in HPLC, was Daicel OD-H, a commercial phase, which allowed the separate collection of the two enantiomers. The chiral selectors used for CE were some cyclodextrin derivatives. The analysis time required from CE was about the half the HPLC enantioseparation time. The biological activity of the rac-mixture and each individual enantiomer was tested against Cryptococcus neoformans and two Aspergillus nidulans strains. The minimum inhibitory concentration (MIC) evaluation showed that the eutomer was the enantiomer chromatographically more retained and had a longer migration time in the electrophoretic enantioseparation. The CD spectrum of the eutomer showed a positive Cotton effect.

Antifungal Agents↗
PubMed2001

Spinal dysraphism in an elderly patient.

Spinal dysraphisms are diagnosed more frequently at birth or in infancy. We report a spinal malformation compatible with lipomyeloschisis in an elderly patient presenting with symptoms and signs of myelopathy. Magnetic resonance imaging revealed an intraspinal mass continuous with a subcutaneous lipoma. Three-dimensional computed tomography reconstructions better showed the spinal dysraphism; dermal sinus was also evident. Neuroimaging can define the precise diagnosis also in elderly patients presenting with myelopathy and can provide valuable structural details.

Aged↗
PubMed2001

A rapid PCR method for the detection of slime-producing strains of Staphylococcus epidermidis and S. aureus in periprosthesis infections.

In periprosthesis tissues, Staphylococcus epidermidis produces extracellular polysaccharide slime. Recently it has been shown that S. aureus also produces slime and that both S. epidermidis and S. aureus contain the ica operon responsible for slime production. In the operon, icaA encodes for N-acetylglutaminyltransferase, the enzyme for polysaccharide synthesis. However, co-expression of icaA and icaD is required for full slime synthesis. The slime-producing strains of both S. epidermidis and S. aureus are more virulent and are responsible for severe postsurgical or periprosthesis infections. The authors describe a simple, rapid, and reliable polymerase chain reaction method to detect icaA and icaD. The method was applied to the detection of ica genes on two reference strains, 15 strains each of S. epidermidis and S. aureus from periprosthesis infections and 10 strains from the skin and mucosa of healthy volunteers. icaA and icaD were detectable only in slime-producing strains (tested for slime production on Congo Red agar), and never in nonslime-producing ones. This method is a straightforward way of detecting the slime-producing ability by S. epidermidis and S. aureus. In clinical specimens this polymerase chain reaction method enables rapid diagnosis of virulent slime-producing strains with respect to the traditional culture method on Congo Red agar, which requires much more time. Rapid identification of the virulent properties of the bacterial strain responsible for a staphylococcal infection is crucial for deciding treatment.

Base Sequence↗
PubMed2001

Evaluation of PCR methods for 5S-rDNA and p30 genes to detect Toxoplasma gondii in blood and other clinical samples.

During the last few years the direct diagnosis of Toxoplasma gondii infection has taken advantage of PCR. The present work tested the sensitivity and specificity of PCR for rDNA and p30 genes. Using ascitic fluid from infected mice rDNA PCR detected 0.5 tachyzoite/ml, while nested p30 PCR 1 tachyzoite/ml. The rDNA amplification was positive in all clinical samples from a single immuno compromised patient (blood, urine and bronchoalveolar fluid). In the same patient nested p30 PCR was positive only in urine and bronchoalveolar lavage (BAL) fluid. The rDNA and p30 amplicons were never found in any amniotic fluids tested. These results could prove the usefulness of rDNA amplification to detect T. gondii in blood.

Amniotic Fluid↗
PubMed1999

Human handedness and asymmetry of the motor cortical silent period.

We performed transcranial magnetic stimulation of the motor cortex in 22 left-handed and 25 right-handed subjects during active contraction of a small hand muscle. Motor evoked potentials had the same latency, amplitude and threshold on both sides of the body, whilst the silent period duration was shorter in the dominant hand. Silent periods elicited by nerve and brainstem stimulation were the same in both hands. Since the latter part of the cortical silent period is due mainly to withdrawal of corticospinal input to spinal motoneurones, we speculate that the results are compatible with the suggestion that tonic contractions of the non-dominant hand are associated with a greater involvement of the corticospinal tract than those of the dominant hand. It also seems likely that there is an asymmetry in the excitability of cortical inhibitory mechanisms with those responsible for the cortical silent period being less excitable in the dominant motor cortex.

Adult↗
PubMed1999

Superficial siderosis of the central nervous system and anticoagulant therapy: a case report.

Superficial siderosis of the central nervous system is a rare condition characterized by deposition of haemosiderin in the leptomeninges and in the subpial layers of the brain and spinal cord. With the widespread use of magnetic resonance imaging, an increasing number of cases of superficial siderosis are being discovered, secondary forms being more frequent than idiopathic ones. We report a 78-year-old man in oral anticoagulant therapy, who presented neurosensory hearing loss, gait ataxia and spastic paraparesis. Magnetic resonance imaging suggested the diagnosis of superficial siderosis of the central nervous system, without an evident bleeding source.

Aged↗
PubMed1999

Determination of silymarine in the extract from the dried silybum marianum fruits by high performance liquid chromatography and capillary electrophoresis.

Silybine (SBN), isosilybine (ISBN), silycristine (SCN), silydianine (SDN), and taxifoline (TXF) are the main active flavanoids, generally found in the dried fruits of silybum marianum. The concentrations of these compounds, excepted TXF, are all together usually expressed as silymarine content. In this paper the determination of the silymarine titre was made by high performance liquid chromatography (HPLC), and high performance capillary electrophoresis (HPCE). Two reversed stationary phases, RP-18 and RP-8, were observed comparing the resolutions of all considered flavanoids with each stationary phases. The HPCE was carried out considering the possible improvement in the resolution of SBN, CN, SDN and TXF using, 8-cyclodextrines or organic modifier. The qualitative and quantitative data obtained by HPLC and HPCE were compared.

Chromatography, High Pressure Liquid↗
PubMed1999

Slime production by Staphylococci isolated from prosthesis-associated infections.

Clinical isolates of Staphylococcus epidermidis are frequently referred to produce a biofilm, known as slime, involved in adherence to medical devices and in resistance to host defences. A high frequency of slime producing Staphylococcus aureus strains was never reported, at least in the case of human isolates. In the present study the production of slime by clinical isolates of S. aureus and S. epidermidis from catheter associated infections and from post-surgical infections was studied by a sensitive method based on culturing the isolates on Congo red agar. The study demonstrates that in nosocomial surgical infections, considered separately from catheter-associated infections, S. aureus emerges as a more prevalent etiologic agent than S. epidermidis, with a proportion of slime producing strains markedly high.

Biofilms↗
PubMed1998

Bio-dissolution of spent nickel-cadmium batteries using Thiobacillus ferrooxidans.

In this study, the production of sulphuric acid in bioreactors with Thiobacillus ferrooxidans attached on elemental sulphur was investigated. These bioreactors reached a maximum H+ productivity of 80 mmol kg-1 d-1 of support. This medium was used for the indirect dissolution of spent nickel-cadmium batteries recovering after 93 days 100% of cadmium, 96.5% of nickel and 95.0% of iron. Moreover, recoveries higher than 90.0% were reached when anodic and cathodic materials were directly added to Thiobacillus ferrooxidans cultures with sulphur as the sole energy source. The results presented show an economic and effective method which could be considered the first step to recycle spent and and discarded batteries preventing one of the many problems of environmental pollution.

Biodegradation, Environmental↗
PubMed1995

Adrenalectomy reduces FGF-1 and FGF-2 gene expression in specific rat brain regions and differently affects their induction by seizures.

We have previously reported that limbic seizures regulate the gene expression of fibroblast growth factor-2 (basic, FGF-2) according to a specific spatio-temporal pattern. In the present paper we have investigated the role of adrenal hormones on seizure-induced elevation of fibroblast growth factor-1 (acidic, FGF-1) and FGF-2 gene expression. Adrenalectomy reduces FGF-2 mRNA expression in specific brain regions, such as frontal cortex, hippocampus and striatum, whereas FGF-1 mRNA levels were decreased only in the frontal cortex. The injection of kainic acid in adrenalectomized rats produced a widespread increase of FGF-2 mRNA with a pattern similar to sham animals as indicated by in situ hybridization. In contrast, although kainate-induced elevation of FGF-1 mRNA in the hippocampus was not influenced by adrenalectomy, its induction in frontal cortex was prevented by this surgery procedure. Taken together, these data indicate that adrenal hormones play a role in the regulation of the gene expression for fibroblast growth factors, but different mechanisms are operative in their induction following seizure activity.

Adrenal Glands↗
PubMed1995

A practical technique for conformal simulation in radiation therapy of pelvic tumors.

PURPOSE: A radiological procedure, based on straightforward conventional methods, was used for a demonstration of pelvic anatomy during simulation to precisely delineate the target volume and increase the probabilities of pelvic tumor control. METHODS AND MATERIALS: Between 1990 and 1993, 450 patients with primary pelvic malignancies underwent external radiotherapy by means of photons, 6-10 MeV, with multiple-field techniques. The simulation was carried out immediately following a pelvic organs opacification (POO) by standard methods. This procedure used a minimal quantity of contrast media (barium sulphate, iodine contrast) and metallic markers to locate directly and simultaneously: (a) small intestine, (b) bladder, (c) rectum, (d) anal canal, (e) bulbous male urethra, and (f) vagina. When all these structures were clearly visualized, the procedure was scored as successfully performed. RESULTS: The sensitivity of procedure was defined as the percentage of successful pelvic organs opacification (POO) carried out in the patients. It was 98% in both women and men. Indirectly, the procedure helped us to locate the prostate, the perineum, and the uterus cervix in the same percentage of patients. Pelvic organs opacification allowed us to document not only the normal position of the pelvic organs tested, but also any variations (ranging from 5% to 40% of cases, after pelvic surgery). Furthermore, POO revealed previously not-reported abnormalities in patients undergoing surgery, mostly rectal stenosis, urinary or anal incontinence, and bladder luxation. The cost of the materials used was $10-15 for each POO, and the time required 5-7 min. The side effects were 7% and not significant. CONCLUSION: In the simulation phase for multiple-field irradiation technique, the simultaneous visualization of pelvic organs obtained by POO procedure allows an exact positioning of the isocenter, an accurate shielding of structures, and finally, a reliable conformal therapy. Due to the low cost, the short length, and the insignificant side effects, POO can be carried out more than once during pelvic treatments for localization and verification of target.

Female↗
PubMed1995

Inhibition of nitric oxide synthase dramatically potentiates seizures induced by kainic acid and pilocarpine in rats.

We investigated whether the severity of convulsions evoked by kainic acid and pilocarpine is modified in nitric oxide synthase inhibitor-treated rats. We found that chronic treatment (4 days) with NW-nitro-L-arginine greatly potentiates seizures induced by both convulsants suggesting a potential role for nitric oxide in mechanisms regulating seizure induction and propagation.

Amino Acid Oxidoreductases↗
PubMed1994

Short- and long-term induction of basic fibroblast growth factor gene expression in rat central nervous system following kainate injection.

Both RNase protection assay and in situ hybridization were used to investigate the effect of intraperitoneal injection of kainate on the messenger RNA levels for basic fibroblast growth factor in the rat central nervous system. Limbic motor seizures were produced by kainate injection and this event was followed by a significant elevation of basic fibroblast growth factor gene expression in rat hippocampus and striatum 6 h after the convulsant injection. The increase in hippocampus was maximal at 24 h and it was delayed with respect to nerve growth factor induction, which peaked 3 h after kainate injection. Animals that suffered prolonged seizure activity also showed a significant elevation of basic fibroblast growth factor gene expression four and 14 days after kainate, when no changes in nerve growth factor gene expression were observed. We show that, within the hippocampus, the increase of basic fibroblast growth factor messenger RNA was localized in dentate gyrus and the CA1 layer 6 and 24 h after kainate injection. Long-term effects on its gene expression were measurable only in the CA1 hippocampal subfield, where major cell damage and astrocytosis have been reported to occur following kainate-induced seizure activity [Ben-Ari Y. et al. (1981) Neuroscience 7, 1361-1391; Lothman E. W. and Collins R. C. (1981) Brain Res. 218, 299-318; Schwob J. E. et al. (1980) Neuroscience 5, 991-1014]. Indeed, the animals which displayed elevated messenger RNA levels for basic fibroblast growth factor four and 14 days after kainate injection showed a marked induction of messenger RNA expression for the astroglial marker glial fibrillary acidic protein. These results indicate that the glutamate analogue kainate produces short- and long-term increases of basic fibroblast growth factor messenger RNA expression with a specific anatomical pattern. Therefore, the gene expression for this neurotrophic factor is probably regulated by neuronal activity at early points in time, whereas the induction observed at later time points is related to adaptive mechanisms taking place following kainate-induced neuronal degeneration.

Animals↗
PubMed1990

Cerebral mapping in subjects suffering from migraine with aura.

Cerebral mapping of the spontaneous electroencephalographic activity was performed in 31 subjects suffering from migraine with aura and the results were compared with those of a matched control group. All the patients were examined during the interictal period. While traditional visual interpretation of EEG records was negative in all but five cases (16.1%) spectral analysis showed an asymmetry in alpha total power over the posterior regions in 13 cases (41.9%) and an asymmetry in alpha band peak frequency in 17 (54.8%). By means of cerebral mapping and statistical significance probability mapping we were able to demonstrate a significant increase in alpha total power in 13 cases (41.9%) and a regional increase in delta and theta total power in 20 cases (64.5%). In comparison with the control group, the migraine patients showed a widespread increase in slow activity (theta and delta) mostly over the temporal regions.

Adolescent↗