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M J Amaral

Publications and source records attributed to M J Amaral.

6 recordsLinked to original sources
PubMed1999

An ultrastructural study of spermiogenesis in three species of Physalaemus (Anura, Leptodactylidae).

Ultrastructural aspects of spermiogenesis and testicular spermatozoa of three anuran amphibians, Physalaemus biligonigerus, P. fuscomaculatus and P. gracilis, were investigated by electron microscopy. The nuclei, middle pieces and tails of the three species were similar. In all cases, the nuclei were elongated and the acrosome consisted of a cone-shaped cap. The connecting pieces located in the flagellum implantation zone had transverse striations. The tails had a 9 + 2 axial filament pattern, a juxtaxonemal fiber and an undulating membrane. In contrast to other Leptodactylidae spermatozoa, no axial rod were observed in these Physalaemus species.

Animals↗
PubMed1993

[Burns. A retrospective study of the Burn Unit of the Hospital de Santa Maria].

A retrospective analysis was made concerning 291 admissions to the Burn Care Unit from June 1987 to March 1992, due to acute burns. Within that considered period of time there was a progressive increase in the number of admissions. Of the patients admitted, patients 177 men were and 144 women. The average age was 33.7 years. The main etiology was thermal injury. The average time of admission was 24.3 days. The mortality rate was 18%. The observer complications were mainly cutaneous and were seen on patients who were lately debrided.

Adolescent↗
PubMed1989

Critical electrolyte concentration of heterochromatin and euchromatin in cells of starved animals.

The critical electrolyte concentration (CEC) of chromatin, considered to be the salt concentration at which the phenomenon of metachromasy is completely abolished, when using toluidine blue as the cationic dye and Mg2+ ions as inorganic cations, was determined for the euchromatin and chromocentral heterochromatin of cells from starved animals. The objective was to determine variations in CEC induced by the starvation stress, which could be related to structural alterations and/or to the composition of these chromatin types. The cells investigated were from Triatoma infestans Malpighian tubules and mouse liver. It was found that the CEC values were affected both by fasting and by refeeding, the effect varying according to chromatin type and the cell system under consideration.

Animals↗