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Biomedical subjects

N Pinto

Publications and source records attributed to N Pinto.

At least 19 recordsLinked to original sources
PubMed2000

Strain-driven morphology of Si1-xGex islands grown on Si(100)

A study has been carried out on the morphology and structure of three-dimensional (3D) SiGe islands grown by molecular beam epitaxy (MBE) on Si(100) substrates. Samples of Si1-xGex alloys have been prepared to investigate the effects either of the alloy composition or of the growth temperature. Atomic force microscopy (AFM) evidenced the growth of 3D islands and transmission electron microscopy (TEM) demonstrated wetting layer growth on Si(100), independently on the deposition conditions. Energy dispersive spectroscopy (EDS) micro-analyses carried out on cross-sections of large Si1-xGex islands with defects allowed a measurement of the Ge distribution in the islands. To the best of our knowledge, these have been the first experimental evidences of a composition change inside SiGe islands. The interpretation of the experimental results has been done in terms of strain-enhanced diffusion mechanisms both of the growing species (Si and Ge) and of small islands.

Journal Article↗
PubMed2000

Vertical facial pattern and orthodontic stability. Part I: Pretreatment vertical pattern and stability.

The occlusions of sixty patients treated by one experienced orthodontist were assessed using the PAR Index. For each patient, pretreatment, post-treatment and long-term follow-up study casts were examined. Follow-up casts were taken at least 6.5 years following the removal of all retention appliances. Following pretreatment cephalometric analysis, the patient sample was divided into three vertical facial subgroups according to the Jarabak Facial Height Quotient. Mean weighted PAR scores were then calculated at each stage for the total sample and for the three subgroups. Mean absolute and percentage occlusal changes were also calculated for the post-treatment period. The relationship between post-treatment occlusal change and pretreatment vertical facial pattern was then studied. The mean weighted pretreatment, post-treatment and follow-up PAR scores were 27.3, 3.3 and 8.0, respectively. The mean-absolute and percentage post-treatment increases in weighted PAR score were 4.7 and 25.4, respectively. No statistically-significant relationship could be found between the pretreatment vertical facial pattern and changes occurring in the weighted PAR score during the follow-up period. It was concluded, therefore, that pretreatment vertical facial pattern, at least on its own, is not likely to be predictive of the amount of post-treatment occlusal change.

Adolescent↗
PubMed1996

[Carcinoma of the oropharynx extended to the base of the tongue: radiosurgical treatment with intraoperative radiotherapy].

Treatment by surgery and postoperative radiotherapy is classical for patients with locally advanced oropharyngeal carcinoma. The poor prognosis of these tumors is associated with the frequency of locoregional relapses, and the survival of the patients treated is more limited according to the initial degree of tumoral involvement of the base of the tongue, which is a critical zone: at this level, the surgical resection must not be too large for a good preservation of the function of the tongue; high doses of radiotherapy are also required here for a fair local tumor control. Intraoperative Radiotherapy (IORT) may be available for delivery of high boosting doses of radiotherapy locally in this target volume. Between March 1988 and March 1992, 39 patients were treated for T3-T4 locally advanced oropharyngeal carcinoma, with 1/4 to 1/2 of the base of the tongue involved; 30 patients were treated for a first localization. Surgery was done by transmaxillary buccopharyngectomy (followed by vascularized myocutaneous flap) for 31 patients with lateral tumors; for 8 patients with median tumor (valleculae), either a conservative susglottic laryngectomy (5 patients) or a total laryngectomy was indicated. Patients treated for the first time underwent also a bilateral node dissection. IORT delivered 20 Gy in the target volume of the resected base of the tongue (prescribed at 90% isodose depth) by the mean of an electron beam of 6 to 13 MeV, with a collimator of 4 or 5 cm of inner diameter. Postoperative radiotherapy was indicated for all patients treated with a first localization. After a minimal follow-up of 6 months, the global survival of 28 patients treated for their first localization was 49% at more than 3 years; 64% of patients treated were locally free of disease. In the same delay, and according to the quality of the surgical resection, the survival of patients treated was 67% and 58%, respectively, if non pathological level of resection was beyond 2 mm, or unless 2 mm from the tumor limit. No complication directly related to IORT was noted. These therapeutic results demonstrate the validity of IORT as a part of a radiosurgical treatment indicated for patients with locally advanced oropharyngeal carcinomas. A longer follow-up of patients treated with a first oropharyngeal tumor is warranted for confirmation of the gain on survival observed.

Adult↗
PubMed1991

Skull bone defects. Preliminary results using a new prosthesis.

The use of a new prosthetic material (110 DTEX F 33 Propylene and Medical Polyester Torlen 165 DTEX) in the reconstruction of bone defects of the skull, even of large dimension, is described by the authors. The material has good biologic tolerance, is already pre-moulded, can be easily adapted to the exact size of the defect and offers remarkable aesthetic and functional results. EEG, X-ray, MRI and CT can be performed without artefact and interferences.

Adolescent↗
PubMed1986

Trends in urolithiasis in various ethnic groups and by age, in Israel.

A survey of upper urinary tract stone composition was carried out over 8 years (1974-1982) in 1147 patients, following a previous survey (1966-1974). Trends in the development of stone formation were found. The most obvious differences were fewer pure calcium oxalate (0.75 versus 5.50%) and uric acid stones (6.11 versus 13.30%) and more mixed stones than in our previous study. In most ethnic groups urinary stones were composed of calcium oxalate/calcium phosphate. A higher prevalence of stones in Israeli-born Jews was noted, in comparison with our previous survey. Age group analysis showed this increase to be limited to the 21-50-year-old group, in contradistinction to a clear decrease in stone formation in Israeli-born Arabs and Jews under the age of 20 years.

Adult↗
PubMed1985

RIA examinations of CSF hormones as a method of demonstrating leakage through the blood-brain and brain-CSF barriers.

Radioimmunoassay determinations of the levels of total T3, total T4, TSH, and prolactin in the CSF were performed on samples taken from 36 healthy individuals. The obtained reference values are the first of their kind. It is considered that RIA determinations of CSF hormone levels may provide a sensitive method for demonstrating pathological leakage through the blood-brain and brain-CSF barriers.

Blood-Brain Barrier↗
PubMed1976

Studies on urolithiasis in Israel.

The composition of 1,000 kidney stones in our area of Israel was analyzed. The predominant stones were a combination of calcium oxalate and calcium phosphate, and uric acid. We used chemical analysis to determine the relative incidence of urinary calculi in 500 patients of various ages and ethnic groups. The incidence of calcium oxalate and calcium phosphate calculi (44 per cent) in Jews born in Israel was lower than in other ethnic groups (54 to 64 per cent). The incidence of uric acid stones in Jews born in Israel, Lebanon, Iran, Iraq and Syria, and the Ashkenazim (16 to 29 per cent) was 2 to 3 times higher than in other groups. In more than 60 per cent of the patients urolithiasis developed after they were 20 years old. The age at onset was significantly younger in Jews born in Israel (25.7 per cent) and North Africa (13.8 per cent), and in Arabs (18 per cent).

Adult↗