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Biomedical subjects

M Simeone

Publications and source records attributed to M Simeone.

18 recordsLinked to original sources
PubMed2005

Effect of sol-gel transition on shear-induced drop deformation in aqueous mixtures of gellan and kappa-carrageenan.

In this work, we present an experimental methodology to investigate the dynamics under shear flow of a drop that is gelling as a consequence of a temperature quench. The experiments were carried out on the system water/gellan/kappa-carrageenan in the biphasic region of the phase diagram, the gellan-rich phase being used as the dispersed phase. Gelation was brought about by lowering the temperature during flow after steady state drop deformation had been reached. Simple shear flow was applied by using a parallel plate apparatus equipped with optical microscopy and image analysis, which made it possible to monitor drop shape evolution before, during, and after gelation. The onset of gelation trapped drop deformation, thus producing anisotropic particles. The fingerprint of gelation was the simultaneous tumbling of the drops, which rotated as rigid ellipsoids under the action of shear flow. Interfacial tension between the two equilibrium phases was determined at different times during the temperature quench by analyzing drop retraction upon cessation of flow. Up to gelation, no significant change was observed in the measured values.

Journal Article↗
PubMed1996

Detection of right ventricular ischaemia during coronary surgery by means of a right precordial lead.

This study was designed to determine the intra-operative incidence of right-sided ventricular ischaemia and any association with left ventricular ischaemia. In 60 patients, undergoing coronary artery bypass grafting surgery, a right-sided precordial lead V5R was used. ST segment deviation of more than 1 mm in V5R was considered significant for myocardial ischaemia. Right ventricular ischaemia occurred in 14 patients (23.3%) but was not associated with left ventricular inferior wall ischaemia. In 4 patients (6.6%) presenting with right ventricular ischaemia, ischaemia of the left inferior wall also developed but in all cases was transient and disappeared by the end of surgery. No myocardial infarction was detected in the post-operative period. The present study showed that the use of a right-sided lead may improve intra-operative electrocardiographic monitoring, by revealing ischaemia in those patients in whom ECG abnormalities were not detected by conventional leads. The transient right ventricular ischaemia recorded in this study was probably related to a reduced hypothermic protection of the right ventricle during aortic cross clamping.

Adult↗
PubMed1991

Minipolymyoclonus in congenital nemaline myopathy: a nonspecific clinical marker of neurogenic dysfunction.

The authors report a seven-month-old boy with severe hypotonia, poor spontaneous movements, breathing difficulties and recurrent respiratory infections, dysmorphisms and a peculiar movement disorder: minipolymyoclonus (MPM), previously reported only in spinal muscular atrophies. MPM is characterized by nonrhythmic myoclonic jerks associated with a rhythmic tremor of the extended fingers polygraphically detected. A muscle biopsy showed pathological changes typical of congenital nemaline myopathy (CNM). The relationship between MPM and CNM may be explained on the presumptive basis of the "neurogenic" nature of this congenital myopathy or by the non-specificity of this clinical sign.

Biopsy↗
PubMed1990

[Ultrasound in endodontics: S.E.M. verification].

After giving a brief illustration of the complex morphology of the root canal system, the Authors discuss the use of ultrasound in Endodontics. Following a critical evaluation of the literature and of the mechanisms of ultrasonic instruments, they illustrate their experience through a wide selection of S.E.M. photographs of teeth treated in vitro with sodium hypochlorite at various concentrations and for different lengths of time. They demonstrate the synergistic action between ultrasound and irrigation solutions, and conclude that the best results are with 2.5% hypochlorite for 1 minute.

Dental Pulp Cavity↗
PubMed1989

[Cardiotoxicity of local anesthetics: dynamic electrocardiogram study].

Twenty-two cardiopathic patients (mean age 54.4 +/- 9.9 years) underwent dynamic electrocardiography during tooth extraction under local anesthesia (mepivacaine hydrochloride 2% plus adrenalin 1:200.000). Heart rate (p less than 0.001), systolic and diastolic blood pressure (p less than 0.001) significantly increased during tooth extraction returning to values near to basal level in the recovery period. No patients showed significant changes in ST segment. One patient with chronic atrial fibrillation presented an increase in ventricular rate (180 beats/min) and appearance of premature ventricular beats, spontaneously regressed. In conclusion, in cardiopathic patients dental operations by local anesthesia with vessel constriction it is possible, provided estimated clinical conditions of patients.

Adult↗
PubMed1989

[Comparison of computerized tomography and sialography in diagnosis of parotid cysts].

In this study it has been valued the differences between T.C. and "scialography" in the parotid gland cystic lesions. Between 1986 and 1987 we examined 100 patients affected by parotid gland diseases utilizing the two different techniques. In 7 patients we diagnosed cystic lesions of parotid gland. Afterwards we compared the results obtained by T.C. and by scialography.

Cysts↗
PubMedDate not supplied

Status epilepticus in benign rolandic epilepsy manifesting as anterior operculum syndrome.

We report the fourth case of partial status epilepticus (SE) in benign epilepsy of childhood with rolandic spikes (BECRS). The child suffered long-lasting attacks involving the mouth and pharynx, clinically manifest as speech arrest, sialorrhea, and drooling. Both clinical and electroencephalogram (EEG) data were compatible with the diagnosis of BECRS. Only during SE was the clinical picture similar to that observed in the operculum or Foix-Chavany-Marie syndrome. SE remission was obtained with the usual antiepileptic drug therapy (diazepam, clobazam, valproate). EEG records showed additional patterns of continuous spike-waves during slow sleep and specific inhibition and blocking of interictal centrotemporal spikes by mouth and/or tongue voluntary movements.

Brain↗