Age- and menopause-related changes in speed of sound and ultrasound attenuation of the os calcis in a healthy Italian female population.

This study assessed changes in ultrasonometric variables of bone (speed of sound, broadband ultrasound attenuation and stiffness) related to age and years since menopause in a normal Italian female population. Two hundred and thirty-one healthy female subjects, age range 18-78 years, divided into two groups (113 pre-menopausal, age range 18-51 years, and 118 post-menopausal, age range 46-78 years), were investigated. The results obtained show that there was a linear decrease in speed of sound, broadband ultrasound attenuation and stiffness with age; a similar pattern was also observed in post-menopausal women as far as the correlations between ultrasonometric variables and both age and years since menopause were concerned. In particular, speed of sound declined at a rate of 0.86 m/s for each year post-menopause, while broadband ultrasound attenuation declined at 0.4 dB/MHz, and stiffness at 0.5 units. These findings suggest that ultrasound variables might be able to detect characteristics of bone that are barely influenced by estrogen deficiency, and depend on other factors. Therefore, ultrasound measurement should be considered as a possible alternative to x-ray densitometry for the assessment of the skeleton.

Ultrasonic parameters of bone in young normals: effect of age and sex.

This study was carried out in order to investigate the early effects of ageing on both broadband ultrasound attenuation and speed of sound through the os calcis. A total of 217 normal subjects, subdivided into 113 fertile women (age range 18-51 years, mean +/- 1 SD=29.4 +/- 8.4 years) and 104 age-matched men (age range 20-49 years, mean +/- 29.3 +/- 7.1 years), were investigated. Mean broadband ultrasound attenuation values in men (127.3 +/- 12.8 dB MHz-1) were significantly higher than those found in women (118.3 +/- 17.2, P < 0.001), whereas no significant differences were found as far as mean speed of sound values was concerned. Both broadband ultrasound attenuation (r = -0.196, P < 0.046) and speed of sound (r = -0.226, P < 0.02) values were inversely related to age in men; only a decrease of speed of sound values with age was noted in women (r = -0.400, P < 0.001). Finally, there was a very high significant correlation between broadband ultrasound attenuation and speed of sound values in men (r = 0.458, P < 0.001), but this was lacking in women. Admitting that the measurement of broadband ultrasound attenuation is influenced not only by bone density but also by trabecular quantity, spacing and orientation, our results seem to indicate that, even during adulthood, and well before the deleterious effects of oestrogen lack become apparent, structural properties of skeletal tissue in female subjects are disadvantageous with respect to those found in male subjects. Furthermore, while there is a progressive and balanced involvement of both the elastic (as reflected by speed of sound) and the structural properties of skeletal tissue of men, an uncoupling between the two is typical of women.

[Immunological phenomena in pulpal-periapical lesions]. / Fenomeni immunitari nelle lesioni pulpo-periapicali.

Based on an extensive review of the literature, the authors examine immunological reactions in pulpal and periapical lesions. Although it has been known for some time that bacterial infection causes this pathology, attention has been recently focused on immunological factors in the ambit of the phlogistic process. The present study examines the correlation between the latter and the type of extent of antigenic response, focusing attention on their important role in the phenomena of osteoclastic activation and inhibition of bone repair. From a physiological point of view there are few inflammatory cells in dental pulp, like macrophages and T lymphocytes. When the pulp comes into contact with the antigenic substance it activates a specific and aspecific immune response: the form through the activation of B and T lymphocytes, and the latter through the action of LPS, PMN and complement. An important role in the immune response is played by the cytokines which are able to regulate the intensity and duration of the immune response against potential pathogenic agents. It was initially thought that these were only produced by lymphocytes and as a result they were known as lymphokines. Later it was observed that other cell populations were also able to produce them. Phlogosis of the periapex starts before the pulp is fully necrotic. Tissue detritus and products of bacterial derivation escape through the numerous endoparadontal communication pathways and stimulate an inflammatory response by the vascular system of the parodontal ligament. The concomitant immune reaction occurs due to the tendency to block and restrict the inflammation to the radicular channels, thus preventing its diffusion.(ABSTRACT TRUNCATED AT 250 WORDS)