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Biomedical subjects

G L Panattoni

Publications and source records attributed to G L Panattoni.

31 records · Page 2Linked to original sources
PubMedDate not supplied

Bone mineral density in the growing human mandible.

The objective of this study was to investigate bone mineral density (BMD) in the growing human mandible by dual-energy X-ray absorptiometry, comparing densitometric data with the nature of the dentition and hence, indirectly, with variation of mechanical stresses. Postero-anterior scans were performed on 58 dried mandibles (between 15 months and 14 years) by a Hologic QDR 1000 X-ray densitometer with "Ultra-Hi-Resolution" software (Hologic Inc., Waltham, MA). The analyses were performed on a polygonal area corresponding to the infero-median region of the mandibular body, and divided into three sections. The sample was divided into two groups according to the appearance of the first permanent molar. A high correlation is detectable between BMD values and age in the group with decidual dentition, while BMD values are significantly less correlated with age in the group with mixed dentition. There are no significant differences between the BMD values of males and females.

Adolescent↗
PubMedDate not supplied

Relations between subcellular events in the degenerating notochord and histopathological features of the spinal chordomas.

The authors focused their attention on the cytology of the degenerating notochord at the level of the vertebral anlagen and compared it with data of the literature on the histopathology of the spinal chordomas. The purpose of the research was to investigate the notochordal histological features justifying the fact that the remnants of a structure destined to atrophy during prenatal life, maintain a proliferative potential in postnatal life. Therefore, from the earliest stages (24th incubation hour) to the terms of development, the notochord was studied by electron microscope in chick embryo. The data obtained show that, in most notochordal cells, signs of metabolic damage and progressive degeneration coexist with signs of secretory and mitotic activity, from which the proliferative potential of these cells seems to derive. Vacuolar degeneration is also likely due to the progressive metabolic segregation of the notochord, owing to the absence of blood-vessels and the appearance of perichordal sheath.

Animals↗
PubMedDate not supplied

Volumetric growth of the different regions of the fetal spine.

The Author analysed the volumetric growth of the spine ("centra" + intervertebral discs) from the 13th week to term of prenatal life. The data were obtained from the osteological collection of the Department of Human Anatomy and Physiology (University of Turin), by means of a geometric procedure. The growth rate was compared with the observations of other Authors on the growth of the linear measures and with the results of previous works on the anteroposterior curvatures of the developing spine. The analysis of the growth in volume of the various spinal regions, seems to admit temporo-spatial relationships only between the growth velocity of the lumbar region and the appearance of the lumbar lordosis.

Embryonic and Fetal Development↗
PubMedDate not supplied

Fetal motor activity and spine development.

The Authors, on the basis of previous data obtained by ultrasonography, analysed more closely the quantitative and qualitative correlations between movements and spine development in the human fetus. The bending angles of cervical lordosis and thoracic kyphosis showed a trend directly and inversely proportional, respectively, to the trend of the overall motility of the fetus, measured as the percentage of time employed by the fetus in motor activity. The trend of the lumbo-sacral angle, that appears later, seemed to be less related to the motor behaviour of the fetus, while the bending angle of lumbar lordosis increases very rapidly when also the fetal motility shows an increase at 25-30 weeks. The significance that the developmental stages and the actions of the muscles involved in early fetal motility, and particularly in spine movements, have in the ossification and in the postural attitude of the axial skeleton, was finally discussed.

Embryonic and Fetal Development↗
PubMedDate not supplied

Body size and thermic exchanges in the human fetus.

On the ground of data obtained in previous works, the trend of the various morphometric parameters, in particular of the body surface area/volume ratio (S/V), and the physio-pathological aspects of this problem, during the human fetal growth was analysed. The S/V ratio, that shows a rapid fall (92% of the initial value) during the 2nd and the 3rd months of development and later on trends to be more and more constant, is the expression of the changes of the shape, as well as the size of the fetus. These changes occur in the period of transition from embryonic to the fetal stage of development and affect the embryo-fetal termic stability, according to extent of the skin surface with respect to the unit of volume. Comparing these observations to the data of the literature, the Authors points out the significance of the S/V value in the radiant heat exchanges between the fetus and the developmental environment, and proposes this ratio for a parameter of the normal fetal growth.

Body Constitution↗
PubMedDate not supplied

X-ray densitometry applied to the study of prenatal ossification.

To evaluate bone mass (BMC) and bone density (BMD) it is possible to utilize x-ray absorptiometry. This method is usually employed in clinical practice for the evaluation of metabolic osteopathies. The authors describe an application of this diagnostic technique to the study of the ossification pattern of the human vertebral column in pre- and post-natal life. On this regard, an ultra high resolution software allowed to analyze quantitative aspects of the ossification of small size vertebral bodies by lateral scans directly performed on bone specimens.

Absorptiometry, Photon↗