Objectives: To obtain further knowledge on the morphogenesis of the articulations in the tympanic ossicular chain in humans. Material and Methods: In 25 temporal bones of human fetuses the structural development of incudomallear, incudostapedial and stapediovestibular articulations was studied. The chronological ages were between the 7th week (21 mm) and the 29th week (270 mm). Results and Discussion: Incudomallear articulation showed diarthrosis and sellar joint characteristics. It showed a homogenous interzone in the 7th week of development, a three-layered interzone in the 8th week, the first cavitation signs in the 9th week and the presence of an articular cavity in the 10th week. The presence of a hyaline cartilage covering articular surfaces was observed starting in the 20th week of development. Incudostapedial articulation showed typical characteristics of a diarthrosis and spheroidal joint with a homogenous interzone at the 7th week, showing similar characteristics for 12 weeks, and completed its cavitation at the 16th week. We observed hyaline cartilage on articular surfaces from 29 weeks. Stapediovestibular articulation showed typical characteristics of syndesmosis. The annular ligament primordium derived from cartilage differentiation, both from stapedial footplate and from the surrounding otic capsule, into mesenchyme and its subsequent transformation into fibrous tissue, reaching definitive characteristics from the 12th week.

The effect of a 13-week high-intensity intermittent exercise program on fiber type composition and the oxidative capacity of rectus femoris skeletal muscle from 20 male Wistar rats (Trained, n = 10; Sedentary, n = 10) was histochemically determined. The training exercise program was developed in a motorized treadmill. It consisted of four running bouts of 2 min duration at 48 ndmin, alternated with recovery intervals of 4 min. Training increased relative cross-sectional area of oxidative fibers (I, [IA, IIX) and decreased the same parameter in type IIB non-oxidative fibers (P < 0,001). Our results suggest that this type of strength exercise program is enough to induce changes in muscle fiber composition. This opens a possibility to use this kind of exercise in preventing and treating muscle atrophy.

In a series of 52 auditory ossicles, their structure and functional significance were studied, with special reference to the patterns of force transmission. The significance of the different degrees of cavitation in the ossicles as well as their eventual pathological significance are also discussed.

In a series of 100 cases, morphological variations of human ossicula tympani were studied. These have seldom been considered either in classic or recent descriptions. Among them, the malleus and stapes are the most variable ones. A geometric model is proposed to systematically study any variation from the typical ossicles. These morphological variations of ossicles could be related to age, sex, race, .and could bring out peculiarities in acoustic transmission.

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The effects on the testis of open-ended vasectomy in the Wistar rat have been assessed morphometrically and evaluated statistically at 1, 4, 12, and 24 weeks after operation, and compared to those in sham-operated controls. The open-ended technique, ie, without ligation of the epididymal end of the cut ductus deferens, allowed drainage of sperm into the spermatic cord. During the period of our study, it did not affect the structure of the testis; although the germinal epithelium, basement membrane, and the stroma and cells of the interstitial space all showed variations when compared to the control group, these were not statistically significant.

No abstract

The inferior epigastric artery seems to be a good candidate for grafting in coronary revascularization because of the low susceptibility to thickening of its intima and the minimal repercussion on its blood flow.