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M C Lucena

Publications and source records attributed to M C Lucena.

9 recordsLinked to original sources
PubMed1986

Morphometric analysis of the rat ventral prostate and seminal vesicles during prepubertal development: effects of neonatal treatment with estrogen.

In a morphometric study on the ventral prostate and seminal vesicles in the rat, we investigated the changes in fibromuscular stroma, glandular epithelium, and glandular lumen. Animals were studied at 15, 30 and 45 days of age. The rapid prepubertal growth started earlier in the ventral prostate than in seminal vesicles. In addition, the effects of neonatal administration of estrogens on the different tissue compartments were studied, comparing rats that had been castrated and/or treated with estrogen at birth to intact animals at 15 days of age. Estrogens caused a decrease in the volume of the glandular epithelium and increased the volume of the fibromuscular stroma in both ventral prostate and seminal vesicles. Castration partially abolished the estrogen-induced growth of the stroma, which suggests that the growth is dependent on testicular factors. The difference in proportion of the fibromuscular stroma between the two glands is evidence that the size of the whole seminal vesicles has increased whereas the size of the ventral prostate has decreased.

Aging↗
PubMed1986

Increased number of mast cells in the testis of neonatally estrogenized rats.

The presence of increased numbers of mast cells in the testis of adult neonatally estrogenized rats is reported. The histometric study revealed significant differences between control and estrogenized animals for two ages considered (45 and 90 days). This increase might be related with the development of connective tissue in estrogenized rats.

Animals↗
PubMed1986

Morphometric aspects of rat testis development.

A morphometric study of rat testis development and ageing (from 5 to 360 days of age) has been carried out. The testicular volume increases from 10.28 +/- 0.35 mm3 (5 days of age) to 1819.43 +/- 52.67 mm3 (360 days of age), showing the most rapid increase between 20 and 70 days of age (22.6 times). The mean tubular diameter increases from 62.25 +/- 1.50 micron (5 days of age) to 280.81 +/- 9.77 microns (360 days of age) and the tubular length from 2.74 +/- 0.18 m (5 days of age) to 25.45 +/- 1.76 m (360 days of age). Up to 15 days of age, the increase in testicular volume was mainly due to the increase in tubular length, whereas from this age onwards the tubular growth was similar in both length and diameter. Tubular development had nearly finished at 70 days of age.

Aging↗
PubMed1984

Effects of exercise to exhaustion in rat myocardium. A stereological study.

Stereological methods under light and electron microscopy have been used to study the ventricular myocardium of rats exhausted by swimming exercise. The proportion of myocardial cell/interstitium diminishes with the exercise. This result is interpreted as a consequence of an intercellular edema which becomes more pronounced during the first hour of exercise. In the myocardial cells, neither the relative volume occupied by the myofibrils nor the number of mitochondria per cm3 undergoes significant changes. Nevertheless, a progressive increase of the relative mitochondrial volume is observed, specially during the first two hours of exercise. This increase may mainly be due to swelling of these organules, since a significant increase of the mean mitochondrial volume was noticed. These features confirm the observations made at ultrastructural level.

Animals↗
PubMed1984

Structural changes in the rat myocardium after exhaustive exercise.

The ventricular myocardium of rats sacrificed immediately after exhaustive swimming exercise showed the following degenerative changes. The organization of the myofilaments varied from an accentuated hypercontraction of the sarcomeres to a disorganization of the same with loss of orientation of the myofilaments and blurring of the Z lines ("contraction bands"). The mitochondria showed an increased swelling along with disorganization of the cristae and narrow joints between the membranes. The nuclei showed an increase in the amount of heterochromatin. All these changes were evident in the first few minutes of the exercise and they reached their maximum level between the first and second hours, diminishing during the second and third hour. The effect produced in the myocardium by this exercise is reversible, since the appearance of the fibres in rats sacrificed at the twelfth, twenty-fourth, and forty-eight hour following the end of the exercise was approaching that of the controls.

Animals↗
PubMedDate not supplied

Effects of neonatal estrogen administration on rat testis development with particular reference to Sertoli cells.

An ultrastructural and morphometric study of the testes in 15-, 22-, 45-, and 90-day-old neonatally estrogenized rats was performed. At 45 days of age, the Sertoli cells appeared immature in estrogenized rats, whereas they were fully mature in the controls. This finding might be related to a deficiency in gonadotropins and androgens during the postnatal period. In 90-day-old estrogenized rats, however, Sertoli cell maturation had occurred, which might be attributed to a recovery of hormone levels. Cytoplasmic alterations, however, such as vacuolation, were present at this age. The morphometric study revealed decreased testicular and tubular volumes as well as decreased mean tubular diameters in the estrogenized animals. In contrast, the absolute tubular length increased more in these animals than in the controls during the period from 15 to 90 days of age. This lengthening process might be related to the large number of hypercurved tubules in the estrogenized rats.

Age Factors↗
PubMedDate not supplied

Ciliated cells in the rat testis effects of neonatal administration of estrogens.

The presence of cells bearing solitary cilia has been studied in the testes of normal and neonatally estrogenized rats. Peritubular myoid cells and undifferentiated interstitial cells showed a higher frequency of cilia in estrogenized animals than in control ones, from 15 to 45 days of age, the differences being slighter at 90 days of age.

Animals↗
PubMedDate not supplied

[Accidental exposure to X-ray from a diffractometer].

The patients's clinical pictures, characterized by an erythema preceding the skin manifestations, their aspect and the occupational histories, made the diagnosis of a radiation accident possible before its dosimetric identification. Doses evaluations using thermoluminescence dosimeters and ionizing chambers correlated well with the clinical estimations. The immediate cause of the accident was poor maintenance of the device that caused its back window to be permanently open, but lack of adequate information on the biological effects of ionizing radiation and on the correct operational procedures were contributory facts. The description of this accident is relevant in virtue of the misconception that such equipment have "virtually no occupational risk". The patients's medical evolutions have had a favorable course, specially because the low energy of the X-ray and its low penetrating capacity. This accident highlights the need for the adequate training of workers on the handling of radiation devices.

Acute Disease↗