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F Prat

Publications and source records attributed to F Prat.

13 recordsLinked to original sources
PubMed1991

Cytotoxic effects of acoustic cavitation on HT-29 cells and a rat peritoneal carcinomatosis in vitro.

Damage to cells and tissues exposed to shock waves (SWs) is thought to be secondary to cavitation phenomena involving the collapse of gas bubbles in a fluid. Using HT-29 cells and DHDK12PROb tumors, we tried to enhance SW-related damage by the simultaneous administration of gas microbubbles. Bubbles resulted from a mixture of air and gelatin (HT-29 cells) or from a carbonated NaCl solution (tumors). HT-29 cells in suspension received either SW (50, 250, or 1000 SWs) alone or in association with bubbles. Trypan blue-negative cells decreased as the number of SWs increased. Exposure to SWs and bubbles resulted in not only an increased but also a delayed mortality as compared to SWs only. One thousand SWs with bubbles induced a complete inhibition of cell growth, with cytoplasmic vacuolae, ruptured membranes, and abnormal nuclear shape and chromatin. Exponential and confluent cells exhibited a similar mortality and growth. DHDK12PROb tumors received either SWs only (50, 100, 250, 500, or 1000 SWs) or SWs with bubbles in vitro. Thymidine incorporation was significantly lower after exposure to SWs with bubbles as compared with controls and SWs only; it was nil by 1000 SWs with bubbles. Histopathological features of tumors exposed to SWs with bubbles included erosion and hemorrhage, disorganized structure, pyknotic nuclei, and cytoplasmic vacuolae. We conclude that cavitation, as produced by a combination of SWs and gas microbubbles, can achieve bioeffects which are relevant to cancer therapy.

Animals↗
PubMed1991

Hepatic lesions in the rabbit induced by acoustic cavitation.

Tissue damage during shock-wave lithotripsy is presumably secondary to cavitation phenomena involving the collapsus of gas bubbles in a fluid. To enhance shock-wave-related hepatic lesions, intravascular gas microbubbles were administered. Three groups of eight rabbits each received either 500 shock waves focused on the right hepatic lobe (group 1), gas microbubbles as a mixture of 50 cm3 of air with 50 cm3 of gelatin infused through an arterial catheter (group 2), or 500 shock waves and gas microbubbles simultaneously (group 3). In group 1, two animals had two to three subcapsular hepatic hematomas (diameter, less than 5 mm) and five had one to five intraparenchymal hematomas (less than 1 mm). In group 2, a moderate liver congestion was observed in three animals. In group 3, all animals had numerous subcapsular and intraperenchymal hematomas (2-30 mm). The hematomas were centered around the portal spaces, associated with lacunae (0.5-5 mm in diameter). Hematomas were also present on the anterior wall of intraabdominal organs. It was concluded that intravascular infusion of gas microbubbles into the path of a shock-wave generator dramatically enhances tissue damage. This technique, potentially useful in the treatment of hepatic tumors, needs refinement to confine lesions in a more uniform pattern to the targeted parenchyma.

Animals↗
PubMed1990

Seasonal changes in plasma levels of gonadal steroids of sea bass, Dicentrarchus labrax L.

Levels of plasma testosterone (T) and 11-ketotestosterone (11-KT) in males and plasma 17 beta-estradiol (E2), 17 alpha-20 beta-dihydroxy-4-pregnen-3-one (17 alpha,20 beta-diOH-P), and T in females were assayed by radioimmunoassay at monthly intervals throughout the sexual cycle of sea bass (Dicentrarchus labrax L.). 17 alpha,20 beta-DiOH-P was maintained at low levels (below 1 ng/ml) throughout the year, even during the spawning period (January-March). A bimodal seasonal pattern of plasma testosterone was observed. Plasma T and E2 levels became significantly increased in December (advanced gametogenesis period) and then showed further increases during January and February (first half of the spawning period) in parallel with the growth of the vitellogenic oocytes. Multiple spawnings of individual females were also observed during the spawning period affecting the relative fecundity of the eggs. A possible role of E2 on this behavior is discussed. In males, both plasma T and 11-KT initially increased in November and then showed further increasings during the rest of the period of gametogenesis (December) to reach their peak levels in the first half of the spawning period (end of January). These increased and sustained higher levels of plasma steroids coincided with the presence of spermiating males. A second peak of plasma testosterone appeared at the end of the postspawning period-beginning of the pregametogenesis period (May-June) both in males and females and their possible role with the preparation of the gonad for the next reproductive cycle is discussed.

Animals↗
PubMed1990

[Lactulose].

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Cell Membrane Permeability↗