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Biomedical subjects

M Dondi

Publications and source records attributed to M Dondi.

At least 19 recordsLinked to original sources
PubMed2006

N3 potentials in response to high intensity auditory stimuli in animals with suspected cochleo-saccular deafness.

We describe a previously un-reported vertex-negative potential evoked by high intensity click auditory stimuli in some dogs and cats with suspected cochleo-saccular deafness. Brainstem auditory evoked potential tracings from 24 unilaterally or bilaterally deaf animals, 22 dogs and 2 cats, among which 21 belonged to breeds with high prevalence of suspected or histologically confirmed cochleo-saccular deafness, were studied retrospectively. Values for latency, amplitude and threshold of this potential in dogs were 2.15+/-0.23 ms, 0.49+/-0.25 microV, and 91.9+/-4.7 dB NHL, respectively (mean+/-SD). Latency and threshold values in cats were in the mean+/-2 SD range of the dog values. Sensitivity to click stimulus polarity and to click stimulus delivery rate pointed towards a neural potential instead of a receptor potential. The vertex-negative wave observed in these animals shares all characteristics with the N3 potential described in some deaf humans with cochlear deafness, where it is presumed to arise from saccular stimulation. The combined degeneration of cochlea and sacculus usually reported in deaf white dogs and cats suggest that N3 may have a different origin in these species.

Acoustic Stimulation↗
PubMed2005

EANM/ESC procedural guidelines for myocardial perfusion imaging in nuclear cardiology.

The European procedural guidelines for radionuclide imaging of myocardial perfusion and viability are presented in 13 sections covering patient information, radiopharmaceuticals, injected activities and dosimetry, stress tests, imaging protocols and acquisition, quality control and reconstruction methods, gated studies and attenuation-scatter compensation, data analysis, reports and image display, and positron emission tomography. If the specific recommendations given could not be based on evidence from original, scientific studies, we tried to express this state-of-art. The guidelines are designed to assist in the practice of performing, interpreting and reporting myocardial perfusion SPET. The guidelines do not discuss clinical indications, benefits or drawbacks of radionuclide myocardial imaging compared to non-nuclear techniques, nor do they cover cost benefit or cost effectiveness.

Cardiology↗
PubMed2004

Myocardial SPECT: what do we gain from attenuation correction (and when)?

AIM: This study aimed at assessing the impact of attenuation correction performed by means of a new hardware device (Beacon(tm)) in the assessment of coronary artery disease with myocardial SPECT and, afterwards, at identifying what specific risk class of patients would mostly benefit from the technique. METHODS: The first 500 consecutive patients, referred to our facility for coronary artery disease (CAD) assessment, were included in this study. Myocardial SPECT was performed after i.v. of 740 MBq of (99m)Tc Tetrofosmin (Myoview, Amersham Health) both after stress and at rest. Studies were acquired by means of a 3 head system (IRIX, Philips Medical System) equipped with the Beacontm option to correct for non-uniform attenuation. Out of the whole population studied, 130 patients underwent coronary angiography (CAG), 108 of which were proven to be affected by significant CAD, defined as a >50% coronary vessel lumen reduction. Attenuation corrected (AC) as well as non-attenuation corrected studies (NAC) were reconstructed, blindly read and qualified as: normal; borderline normal; borderline abnormal and definitely abnormal. RESULTS: In the group of 130 patients who underwent CAG, sensitivity for CAD detection did not vary significantly (96% and 93%, for NAC and AC studies, respectively, p=ns) whereas specificity increased from 73% (NAC studies) to 91% (AC studies), p<0.01. Normalcy rate, assessed in a small subgroup (n=21) with a <5% likelihood for CAD, was found to be 80% for NAC studies vs 93% for AC studies (p<0.05). As regards synthetic clinical judgements, when we grouped normal and probably normal readings into a single ''normal'' category and, conversely, probably abnormal and definitely abnormal into a single ''pathological'' category, we see that after attenuation correction studies reported as ''pathological'' are reclassified as ''normal'' in 17.8% of the cases (25.2% in males and 6.9% in females, p<0.05). The opposite is seen in only 1.6% of the cases (1.3% in males and 4.4% in females). According to established criteria, 155 patients were classified at low risk for CAD (<15%), 115 at intermediate risk (from >15% to <50%) and 230 at high risk (>50%). The intermediate risk class showed the greatest impact: ''normal'' findings increased from 52% to 72%, thus reducing the rate of ''pathological'' reports from 48% to 28%. CONCLUSIONS: This study shows that, while sensitivity for CAD is not affected by attenuation correction, specificity increases significantly, as well as normalcy rate. Out of the whole population studied, the main finding was that attenuation correction increases the rate of normal reports, more frequently in males than in females, and that studies carried out in patients at intermediate risk for CAD are more likely to be affected.

Aged↗
PubMed2001

Evaluation of thrombogenicity of fluoropassivated polyester patches following carotid endarterectomy.

The use of a patch after carotid endarterectomy (CE) is recommended to reduce the incidence of restenosis. Most studies on this subject report the implantation of saphenous vein or PTFE patches, because polyester has always been considered to be a thrombogenic material. The purpose of this study was to evaluate the thrombogenicity of a knitted polyester patch passivated by fluoropolymer surface treatment (FPD patch), which experimental studies have demonstrated to be less thrombogenic than other materials. This prospective, randomized study was performed in 22 patients who underwent CE. In 11 patients the arteriotomy was sutured directly, while in the other 11 an FPD patch was applied. Patients' 111in-oxine labeled platelets were reinjected on the first postoperative day, and scintigraphies were performed after 4, 24, and 48 hr, respectively. The study confirmed that an FPD patch is no more thrombogenic than a simple carotid endarterectomy. The application of the patch, therefore, can be recommended to reduce restenosis without any adjunctive thromboembolic risk.

Aged↗
PubMed2001

Retrospective analysis of the association of nodular goiter with primary and secondary hyperparathyroidism.

BACKGROUND: The association of hyperparathyroidism (HPT) with thyroid disease has long been known, but the mechanisms underlying such an association have not yet been clarified. OBJECTIVE: To elucidate the main factors determining this combination of endocrine diseases, in a retrospective multicenter study. METHODS: We retrospectively reviewed all patients referred for parathyroid scintigraphy in the period 1990-1999. A total of 487 patients in the age range 17-65 years were selected for the analysis (339 women and 148 men); group A included 241 patients with primary and group B 246 patients with secondary HPT. RESULTS: A total of 124/241 patients in group A (51.5%), but only 92/246 patients in group B (38.2%) had thyroid disorders (notably nodular goiter) associated with HPT (P=0.0035). Thyroid disorders were evenly distributed throughout the entire 17-65 years age range in group A, but 17-40-year-old patients in group B had significantly fewer thyroid disorders than the older patients of the same group (15.5% compared with 43.3%, P<0.002), as expected in a general population. In patients with primary HPT there was no difference in the prevalence of thyroid disease between women and men, whereas the ratio of women to men in secondary HPT patients with thyroid disease was about 3:1. CONCLUSIONS: These results demonstrate an increased prevalence of nodular goiter in patients with primary rather than secondary HPT, and are consistent with a possible role of increased endogenous calcium concentrations (a hallmark of primary, but not of secondary, HPT) as a goitrogenic factor in patients with HPT.

Adolescent↗
PubMed2000

Decomposition of nitrous oxide on pillared clays.

Alumina-pillared smectites have been found to abate nitrous oxide in the presence of methane. The results indicate that the yield of the reaction (N20 --> N2 + (1/2)O2) increases when pillared clays are exchanged with transition metals, single-pass conversion rates of >70% being attainable. In particular, when double exchanged (calcium and subsequently copper) alumina pillared montmorillonite/beidellite is used as a catalyst, de-N2O activity reaches a maximum, which is maintained even after 4 h of work at a space velocity of 5.5 h(-1). A mechanism for the reaction is suggested, which implies that N2O is first adsorbed by the catalyst and then decomposes through two different paths: catalyst oxidation and catalyst reduction. Such a redox process explains the kinetic data.

Environmental Pollution↗
PubMed1999

High-performance liquid chromatography study of the enantiomer separation of chrysanthemic acid and its analogous compounds on a terguride-based stationary phase.

The direct enantioseparation of chrysanthemic acid [2,2-dimethyl-3-(2-methylpropenyl)-cyclopropanecarboxylic acid] and its halogen-substituted analogues was systematically studied by HPLC using a terguride-based chiral stationary phase in combination with a UV diode array and chiroptical detectors. Isomers with (1R) configuration always eluted before those with (IS) configuration. The elution sequence of cis- and trans-isomers was strongly affected by mobile phase pH, whereas the enantioselectivity remained the same. Conditions for the separation of all the enantiomers were also examined. This method was used for monitor the hydrolytic degradation products of Cyfluthrin (Baythroid) in soil under laboratory conditions.

Chromatography, High Pressure Liquid↗
PubMed1999

Can newborns discriminate between their own cry and the cry of another newborn infant?

Two experiments were conducted to test whether newborns could discriminate between their own cry and the cry of another newborn infant. Facial behavior and nonnutritive sucking rate were adopted as dependent measures. In Experiment 1, 20 newborns in an awake state were presented with either their own cry or the cry of another infant. In the latter condition, newborns showed the facial expression of distress more frequently and for a longer duration. In addition, the rate of sucking decreased significantly between the pretest phase and the 1st min of presentation of another infant's cry. Newborns' responses, although delayed and less intense, showed a similar trend in Experiment 2, during which 20 newborns in a sleep state were tested with the same procedure. These results indicate the newborns' capability to discriminate between the 2 cry stimuli and show the effectiveness of a newborn cry in inducing distress signals in another newborn infant.

Crying↗
PubMed1998

Characterization of a small chondroitin sulfate proteoglycan isolated from the mucus surrounding the embryos of Viviparus ater (Mollusca Gastropoda).

A small chondroitin sulfate proteoglycan was isolated and partially characterized for core protein and glycosaminoglycan structures from the mucus surrounding embryos in the developmental pouch of Viviparus ater (Mollusca Gastropoda). The protein bearing polysaccharide nature was confirmed by gel-permeation chromatography separation of fractions positive to the uronic acid dosage, 7.5% SDS-PAGE under reducing conditions, sequential staining with alcian blue and ammoniacal silver. Its molecular mass was calculated at about 228,800. After degradation of the galactosaminoglycan components by chondroitinase ABC in the presence of proteinase inhibitors, the molecular mass of the core protein was determined at about 72,200. Treatment of the proteoglycan with keratanase did not modify its electrophoretic migration. Isoelectric focusing of the core protein demonstrated a micro-heterogeneity with the presence of two isoforms with different isoelectric point, pI=8.2 and 6.6, in a ratio of about 1:2.2. The glycosaminoglycan component of the proteoglycan was characterized as chondroitin sulfate with a molecular mass of about 30,750 composed of 5% non-sulfated unsaturated disaccharide, 94% monosulfated disaccharides (4-monosulfated to 6-monosulfated disaccharide ratio of 1.36) and 1. 5% disulfated disaccharides (in particular 1.3% 2,6-disulfated disaccharide) with a sulfate to carboxyl ratio of 0.96. Degradation of the chondroitin sulfate with chondroitinase ABC and ACII permitted to determine a percentage of glucuronic acid of about 78.4. The proteoglycan isolated from the mucus surrounding the embryos of Viviparus ater is formed by a small core protein bearing about five chondroitin sulfate chains (80% chondroitin sulfate/20% dermatan sulfate) with potential function in the developmental processes of molluscs embryos.

Animals↗
PubMed1998

MAIA project: software for the management of toxicodependence treatment process.

This chapter reviews the importance of information management in a therapeutic community, how to select the data collected by the interview and features of the software and its fitting in an operative context. New sections are projected to help staff who diagnose treatment candidates and treat patients. Use of statistical analysis as an instrument for management of therapeutic communities is based on the experience of "Centro Solidarietà di Modena". Some examples are included on the population of "Centro Solidarietà di Modena". Artificial neural networks have a viable role for treatment (primary, secondary and tertiary).

Adolescent↗
PubMed1996

Bartter's syndrome: renal scintigraphic appearance after captopril administration.

We report a case of Bartter's syndrome, a rare disease characterized by hypokalemia, increased plasma renin and angiotensin II levels with normal blood pressure. During the diagnostic work-up, the patient had renal scintigraphy in baseline and after captopril administration. Pharmacological blockade of the renin-angiotensin system with captopril resulted in bilateral and symmetrical renal abnormalities (increase of parenchymal transit time, time to maximum activity and retained cortical activity, with cortical trapping of the radiopharmaceutical). Baseline scintigraphy was normal. The findings are consistent with Bartter's syndrome pathogenesis. Captopril renography may be useful to differentiate Bartter's syndrome from other covert causes of hypokalemia.

Adult↗
PubMed1995

Effects of acetylsalicylic acid on serotonin brain receptor subtypes.

1. The lysine salt of acetyl salicylic acid (ASA) at a dose equivalent to 400 mg/kg of acetyl salicylic acid (ASA) was intraperitoneally administered in rats. 2. After 30 and 120 min ASA did not modify the number of receptors nor the affinity of [3H] 8-OH-DPAT binding sites in pons and cerebral cortex. On the other hand, the receptor number in the cortex membranes decreased significantly using [3H] ketanserin as ligand, while the receptor number in the pontine membranes did not change. 3. These data support the involvement of central 5-HT receptors in the mode of action of ASA.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1995

Determination of individual renal function through noninvasive methodologies.

Radioactive tracers provide a unique means of determining individual renal function and are therefore to be preferred for obtaining accurate information on the functional status of each kidney. New applications of computed tomography and magnetic resonance imaging appear promising, but results from large studies are not available to confirm their potential role.

Glomerular Filtration Rate↗
PubMed1995

Assessment of myocardial viability after thallium-201 reinjection or rest-redistribution imaging: a multicenter study. The Italian Group of Nuclear Cardiology.

UNLABELLED: To establish the real nature of 201Tl defects in the assessment of myocardial viability (e.g., fixed versus reversible), 201Tl reinjection was evaluated in a multicenter trial involving 402 consecutive patients with ischemic heart disease and exercise 201Tl defects. METHODS: Twelve hospitals, using the same type of gamma camera and computer software, adopted one of the two most widely used reinjection protocols. In 230 patients (Group A), reinjection was performed immediately after stress-redistribution planar imaging; in 172 patients (Group B), reinjection was performed on a separate day and followed by rest-redistribution imaging. The images were interpreted by three blinded observers in a core laboratory on a five-point qualitative scale; the reproducibility in visual scoring was excellent. RESULTS: Groups A and B had a similar prevalence of myocardial segments with abnormal uptake at stress (39%, 40%), as well as with reversible (16%, 17%), partially reversible (21%, 19%) and irreversible (63%, 64%) defects at redistribution. After reinjection, 201Tl uptake improved in 27% and 36% of both partially reversible and irreversible defects in Groups A and B. No differences were found when comparing early and delayed reinjection imaging in Group B. CONCLUSION: This study confirms the validity of 201Tl reinjection in a large, unselected population, but the discordance with stress/redistribution is less than has been previously reported for both 201Tl reinjection protocols, the prevalence of improved segments after reinjection was higher with the separate day approach.

Exercise Test↗
PubMed1994

Early pulmonary involvement in systemic sclerosis assessed by technetium-99m-DTPA clearance rate.

UNLABELLED: Systemic sclerosis (SS) is frequently associated with interstitial lung disease, but clinical symptoms and radiologic abnormalities may occur late in the course of the disease. This study investigated early pulmonary involvement by assessing the clearance rate of inhaled 99mTc-diethylenetriaminepentaacetic acid (DTPA). METHODS: Sixteen patients with proved SS, no clinical pulmonary symptoms and normal chest radiogram were prospectively studied. The 99mTc-DTPA clearance rate was calculated as the time to half clearance (T1/2) and compared with values obtained in healthy nonsmokers. RESULTS: Six patients showed abnormally increased clearance (T1/2 < 53 min). Rapid clearance was not correlated to SS disease duration or to abnormal pulmonary function tests. Five of six patients with abnormally increased clearance underwent high-resolution CT, which in all five demonstrated pathologic findings that were suggestive of early interstitial disease. CONCLUSION: These findings indicate that in SS asymptomatic patients may frequently present with abnormal 99mTc-DTPA clearance; 99mTc-DTPA lung scintigraphy may allow early detection of subclinical pulmonary involvement in SS.

Adult↗