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Biomedical subjects

M Neroni

Publications and source records attributed to M Neroni.

At least 19 recordsLinked to original sources

Multiple skull base meningioma: case report.

BACKGROUND: The incidence of multiple skull base meningiomas varies from 1 to 3% in different series. Skull base meningiomas are rare. The pathogenetic role of low-dose radiation seems to be fairly well established in the oncogenesis of meningiomas. Calvarial location and multiplicity seem to be among the distinctive features of radiation-induced meningiomas. Skull base location is a very rare occurrence, mainly because the path of irradiation does not significantly involve this region. CASE REPORT: We describe a rare case of simultaneous occurrence of two skull base meningiomas in a 66-year-old female. This patient underwent low-dose irradiation for tinea capitis when she was 8 years old. The patient complained of nuchal pain, paresthesias in both hands, and progressive weakness on her right side. She was admitted to the hospital in September 1994. An MRI showed two masses, one located at the level of the tuberculum sellae and the other at the foramen magnum. These seemed very likely to be multiple meningiomas. The latter lesion, which was more symptomatic and dangerous, was operated on first. Six months later, elective treatment of the suprasellar meningioma was performed with success. CONCLUSION: The actual role of previous head irradiation in the oncogenesis of the present meningiomas remains somewhat unclear. Proper management and judicious use of skull base surgery techniques were key factors in the successful treatment of the patient.

Aged↗

Diaphragma sellae metastasis from colon carcinoma mimicking a meningioma. A case report.

We describe a rare case of metastatic intra-suprasellar adenocarcinoma from colonic cancer mimicking a meningioma of the "diaphragma sellae". Autopsy studies indicate breast and lung carcinoma to be the most frequent primary tumor metastasizing this site, particularly in patients with systemic spread. While diabetes insipidus is reported to be one of the commonest symptoms in these cases, the only clinical manifestation of the tumor in our patient was a bitemporal hemianopia, while the primary tumor remained asymptomatic. In the available literature are reported only two pituitary metastasis from operated colon carcinoma. In both cases the diagnosis of the colon cancer preceded the pituitary operation. The clinico-pathological and neuroradiological aspects of this unusual lesion are analyzed in the light of the relevant literature on the topic focusing on recent MRI acquisitions.

Adenocarcinoma↗

Intracerebral Aspergillus abscess: case report and review of the literature.

Intracranial aspergillosis is a rare pathologic condition, difficult to treat and often fatal, which generally affects immunodepressed patients. A case of brain abscess secondary to pulmonary localization in a patient with a non-Hodgkin lymphoma is described. The most significant clinico-pathological findings of intracranial aspergillosis are examined in the light of the relevant literature.

Aspergillosis↗

[A microscopic evaluation of the marginal adaptation of onlays in gold].

The aim of this in vitro trial was to evaluate the marginal seal and adaptation of gold onlays according to the instrumentation used to prepare the bevels, the quality of margins (as cast vs. polished in the laboratory) and two different finishing procedures (burnishing during or after setting of the cement). For that purpose, 25 freshly extracted human molars were restored with onlays using standardized preparation and fabrication methods. The marginal adaptation of the cemented onlays was evaluated using replicas and scanning electron microscopy. The marginal seal was evaluated on sample sections after a dye infiltration test. In order to improve the marginal fit of gold onlay restorations, it can be recommended to: use diamond burs (Intensiv no. 32 and 37) to prepare the bevels finish and polish restorations in the laboratory except for areas with access to clinically burnish, and polish the margins after setting of the cement.

Crowns↗

[The in vitro testing of the sensitivity of human cryopreserved pulp cells].

The purpose of this in vitro study was to evaluate the sensibility of frozen human pulp cells, in order to examine the cytotoxicity of dental products. The cell cultures and the biological assessments, using still incomplete human premolars and pulp germs, were achieved according to a standardized method. The sensibility of frozen cells was assessed by comparison of cell reactions before and after 1, 3 and 6 months of congelation, for two dental products called Aquacem and Pulpdent, the cytotoxicity and biocompatibility of which were further confirmed. The behaviour of cells with and without congelation was microscopically evaluated, the growth and morphology of cells were assessed after 7, 14, 21 and 28 days. The comparison of the results showed a similar behaviour between cells with and without congelation, except for few cell alterations in the form of granula which occurred during a short period, probably due to the congelation process. This cell liability offers the opportunity to elaborate a bank of cells available on demand for preliminary cytotoxicity assessments.

Acrylic Resins↗

[6 dentin adhesive products subjected to controls in vitro].

The aim of this in vitro study was to assess of the biocompatibility of 6 adhesive dental products (Cavalite, Dual Cement, Fuji Type II, Gluma, Ketac Bond, Scotch Bond) using cell cultures of human pulps and a standardized method. It was thus possible to improve the scale of biological activity proposed by Regad et al., (1989). The specific behaviour of the cells in the contact and adjacent zones has been added to the assessment of the cellular reactions of the whole culture. These criteria allowed the clear differentiation of the toxicity and the biocompatibility of the products. The following estimations were made: Gluma and Fuji Type II "toxic", Cavalite "acceptable", Scotch Bond "not significant", Ketac bond and Dual Cement "acceptable" and "not significant" with a "toxic" tendency.

Acrylic Resins↗

Simultaneous foveal and parafoveal electroretinograms in hereditary degeneration of the central retina.

Simultaneous foveal and parafoveal electroretinograms (ERG) in response to two identical checks (6 degrees per side) alternating at constant mean luminance were recorded in 26 patients (52 eyes) affected by central hereditary chorioretinal diseases and in 14 age-matched normal subjects (14 eyes). Patients were divided into four groups according to clinical diagnoses: 1. Stargardt's disease; 2. cone dystrophy; 3. vitelliform degeneration; 4. pattern dystrophy. The amplitude and latency of the foveal ERG and the amplitude ratio between foveal and parafoveal ERG (F:PF ratio) were measured. The mean foveal ERG amplitude was significantly lower than the control mean in all patient groups. The foveal ERG latency showed a trend to a increase in all pathological groups. However, this difference was not statistically significant. The mean value of F:PF ratio was significantly reduced as compared with the control mean in Stargardt's disease and cone dystrophy only. In 46 of 52 affected eyes (88.5%) at least one of the electrophysiological parameters was abnormal. Our results suggest that the simultaneous foveal and parafoveal ERG recording may be a sensitive technique in hereditary degenerations of the central retina. This method may also contribute to a better understanding of cone degeneration pathophysiology.

Adolescent↗

Development of personal computer software for a visual electrophysiology laboratory.

This paper describes the software developed by the authors in order to introduce the flexibility and computing power of a modern personal computer in an existing visual electrophysiology laboratory. The basic problems that a programmer must solve in order to implement the main tasks requested are discussed. Such problems include signal acquisition, signal averaging, artifact rejection, time domain analysis, frequency domain analysis and data management. The software developed following our guidelines makes it possible for a personal computer equipped with a commercial analog-to-digital converter to interface directly with the physiologic amplifiers and visual stimulators commonly used either for classical electroretinography or for pattern and focal electroretinography.

Electroretinography↗

[Substitute model of an in-vitro biological trials. I. Standardized method using human pulp cells].

To ascertain the biocompatibility of dental materials, an in vitro biological test using cultures of human pulp cells was designed as an alternative to the in vivo method using human teeth. The cells were cultured from fresh explants of pulp germs and the 4th generation of cells (P4) was shown to be very similar to the controls. The comparison between the results of the in vitro cell cultures (obtained by rating the cells' growth and the histomorphology) and those of the controls (histologic rating of the pulpal response) indicated that the developed cell culture method was suitable for the preliminary evaluation of pulpal protective materials.

Biocompatible Materials↗

[Substitute model for in-vitro biological testing. II. Quantitative evaluation of the biocompatibility of dental products].

A biological model for evaluating pulpo-dentinal capping materials is described. The model uses cultures of human pulp cells which are explanted to form cell monolayers. Four products already tested in vivo on teeth subsequently extracted for orthodontic reasons were laid directly over these cultures and observed after 7, 14, 21 and 28 days, corresponded to the in vivo test periods. The growth and morphology of the cells were similar for both test systems, indicating comparability between the two biological models as well as the validity of the developed in vitro method. A preliminary scale of biological activity is proposed which could be useful for preliminary screening of materials.

Biocompatible Materials↗

Changes in spatial tuning of the pattern electroretinogram with age.

Experimental and clinical studies have demonstrated that the electroretinogram in response to periodical patterns alternating in contrast at constant mean luminance (pattern reversal ERG, P-ERG), is correlated with ganglion cell activity. Senile functional changes of these neurons might be therefore investigated by the P-ERG technique. Steady-state P-ERGs (8 Hz) in response to sinusoidal gratings of different spatial frequencies (0.6-6.8 c/d) were recorded in normal subjects ranging over 50 year age span. The P-ERG amplitude as a function of stimulus spatial frequency shows a maximum between 1.2-1.7 c/d and attenuation at higher and lower spatial frequencies (spatial tuning). The P-ERGs of the older subjects are reduced in amplitute, as compared to those of the younger ones, over the whole range of spatial frequency. This reduction is more marked at intermediate spatial frequencies resulting in a shallower tuning.

Adult↗

Macular electroretinogram as a function of age of subjects.

Macular and paramacular electroretinograms in response to two adjacent checks (6 deg/side), alternating at constant mean luminance, were recorded in 34 normal subjects ranging in age from 16 to 74 years. The macular electroretinogram declines progressively in amplitude with age (R = -0.42; P = 0.013). The amplitude ratio between macular and paramacular responses tends to be independent of age (R = -0.21; P = 0.22). Age-related changes in the macular electroretinogram shown in our study are consistent with previous anatomical and functional studies, which indicate a deterioration of photoreceptors beyond 20 years of age. These results suggest a possible use of this technique for future studies on macular degeneration.

Adolescent↗

Simultaneous macular and paramacular ERGs recorded by standard techniques.

A technique for the simultaneous recording of two small-field electroretinograms (ERGs), macular and paramacular, employing standard apparatuses for stimulation and analysis is described. The stimuli consisted of two adjacent checks (6 deg/side) obtained by masking the display of a commercially available TV pattern stimulator. The checks were square-wave-modulated in counterphase at 3.12 Hz. The subjects fixated the center of one of two checks. In one stimulus cycle, two ERGs could be distinguished: one from the macular area and the other from the adjacent area. The macular ERG is about twice as large as the paramacular. ERGs recorded by this technique can be considered focal since (i) they show a sharp fall-off in amplitude when the stimulus is displaced from the fovea, and (ii) they are no longer recordable when the stimulus is centered on the optic disk or on a large macular scar.

Electroretinography↗

Statistical analysis of clinical breast cancer by computer.

At the moment we still lack a clear correlation of clinical staging and pathology with therapy and prognosis in breast cancer patients. More studies need to be conducted dealing with the relationships of breast cancer to previous diseases, hormonal balance, conservative therapy and type of surgical therapy. These evaluations may be very important in supporting a less serious prognosis, a clearer clinical staging and a more certain choice of the right therapy. With computer help we have evaluated data from 500 patients with breast cancer. We have considered: age; previous breast diseases with particular regard to therapy; hormonal balance; obstetrical relevant past history; morphological and functional aspects of the breast; the histology of the tumour and metastases; and the results of therapy.

Breast Neoplasms↗