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Biomedical subjects

S Rouy

Publications and source records attributed to S Rouy.

27 records · Page 2Linked to original sources
PubMed1984

The morphological effects in pig liver after Nd-YAG laser resection.

The morphological effects of liver resection in 15 pigs performed with a Nd-YAG laser beam are reported. A regular cut surface was obtained and overlayed an ischemic layer which was thinnest at a 80 W power output and a short exposure time. Hemostasis was satisfying when the encountered vessels did not exceed 4,5 mm in diameter. Semi-thin and electron microscopic examination showed "ghost" cells in the layer of coagulation necrosis, shrunken hepatocytes and red blood cells in oedematous layer and "swollen" mitochondria in the deepest layer. Clamping of the hepatic pedicle - increasing local hyperthermia by suppression of cooling vascular inflow - majorated the depth of cellular alterations and the intensivity of the post-operative inflammatory reaction. Numerous biliary ductules and active hepatocytes meant parenchymal regeneration. Good healing evolution free of complications was observed after a one year's follow up.

Animals↗
PubMed1984

[Influence of pedicle clamping in partial hepatic resection with the Nd YAG laser. Comparative study in a series of 15 pigs].

Liver resection is performed in 15 pigs by means of low divergent Nd YAG laser, the hepatic pedicle being clamped and not. Clamping does not modify the efficiency of laser hemostasis during resection but increases the thickness of the ischemic layer underlying the cut liver edge. The coagulation necrosis and the edematous layer are more thickened. Migration of inflammatory cells and young fibrosis present at day 3 are gaining ground until day 15. During the same period, biliary neoductules and nodules of hepatic regeneration appear. Hepatic inflow being conserved, these reactions are delayed and less intensive. The hyperthermia, the inflammatory cellular reaction and the deepness of parenchymal damages induces by pedicle clamping are suitable for antitumoral surgery. Cooling effects of hepatic inflow are better for traumatic surgery.

Animals↗
PubMed1983

Hepatic resection with an Nd:YAG laser in pig.

Eleven hepatic resections were performed by means of a divergent Nd:YAG laser. The beam was transmitted through a fiberoptic delivery system without any handpiece. The shortest resection time and most limited ischemic damage (4 mm) were obtained with 80-W power shoots and a low divergent beam (4 degrees 2 for full angle). The hemostatic effects of the Nd:YAG controlled bleeding from veins of up to 4.5 mm in diameter, and parenchymatic oozing from the cut edge minimized blood loss. Histological examination revealed the importance of cellular deterioration in the ischemic layer, while electron microscopy showed selective destruction of cell organelles and protein denaturation. Marked elevation of hepatic serum enzymes suggests a high degree of cellular damage. Postoperative examinations confirmed an uncomplicated healing process. Finally, the use of a flexible fiberoptic enables easy surgical manipulation.

Animals↗
PubMed1983

[Histological aspects of congestive cardiomyopathy caused by alcohol. Comparison with so-called primary cardiomyopathies].

The endoventricular biopsies of nine patients with alcoholic congestive cardiomyopathy were studied under the light microscope and under the electron microscope. These were compared with the results of nine cases of primary congestive cardiomyopathy, at a similar clinical stage. In the absence of specific signs, the overall appearance on both light and electron microscopy is sufficiently suggestive to allow differentiation of the two forms of cardiomyopathy. Repeated biopsies revealed disappearance of the nuclear abnormalities after withdrawal of alcohol, which introduces a prognostic element.

Adult↗
PubMed1979

[Round cells of human sperm].

Many round cells are found whose number may become conspicuous. These cells may originate as well from germinal as from somatic lines. Electron microscopy is the only way to distinguish the two kinds of origin. In some specimens germinal cells predominate (spermattids, plurinuclear cells), in others there are many phagocytic cells which may ingest a great number of spermatozoa and this phenomeon may stimulate an azoospermy by failure of spermatogenesis. The study of human sperm (or testicular biopsies) by electron microscopy is needed to obtain the necessary information in order to orient diagnosis, prognosis and therapy.

Cell Nucleus↗
PubMed1977

[Ultrastructural characteristics of human spermatozoa with elongated head (author's transl)].

In most spermatozoa with elongated head persists an abundant complex membranous system between the post-acromial zone and the post-nuclear region. This system has a periodical structure, the apparently spherical unit of which is 120 A in diameter; it develops between the two sheaths of the nuclear envelope and seems to be continuous with the innermost one. This system can be seen in spermatids during normal spermiogenesis and in most cases it seems to be eliminated either with cytoplasmic droplet or by swelling into the nucleus. Now, a comparable but permanent structure is located all around the head of the normal spermatozoon at the height of the posterior part of the post-acrosomial sheath. This latter system is organized under plasma membrane and only visible on the ultrathin sections made with an appropriate incidence. For some authors it might contribute to maintain the integrity of the head and that of the neck of the spermatozoon and so it might be comparable to a system of septal desmosomes. For other authors periodic structures might favour adherence and fusion of spermatozoon with ovocyte during fertilisation. The particular membranous system that we describe persists often in the spermatozoon with elongated head, by its exuberance it can trouble or delay the fusion of the two gametes at the moment of fertilisation, which might explain the sterility of men bearing this anomaly.

Acrosome↗
PubMedDate not supplied

[Hepatic resections using an Nd YAG laser. Anatomic and biological results of an experimental study].

Experimental hepatic resections were performed with a Nd YAG laser in 32 New-Zealand rabbits. The beam was simply transmitted by a quartz fiber of 4 degrees 2 and 8 degrees in divergence for the full angle, without any focalization. Section was possible at a power output superior to 20 W requiring short cutting time. Complete hemostasis was obtained as long as the diameter of encountered vessels did not exceed 4,5 mm. Immediately after resection the parenchyma was covered by an ischemic layer varying from 2 to 8 mm. Its thickness rapidly increased to high levels whenever the power output exceeded 40 W or when hepatic pedicle was clamped. Healing process was installed at day 30. There was no hemorrhagic, biliary or septic complication. Eleven animals were alive eight months after. Histological examination revealed four layers: a first one of carbonization, a second of condensed cells, a third of edema presenting disruption of sinusoids, and a fourth one composed of progressively normal tissue. Peripherical veins presented thrombosis of their blood content and coagulative necrosis of their wall while bile canaliculi were preserved. Fibrosis appeared in the edematous layer the 10th day and was completely formed at day 30. Electron microscopic examination revealed shadowy cells embedded in the condensed layer and mitochondrial alteration in the edematous layer. The 15th day foci of cell regenerations were registered. High levels of SGOT, SGPT and LDH (fractions IV and V) were observed immediately after resection.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine Transaminase↗
PubMedDate not supplied

[Vascular microanastomosis with diode laser. Control study and morphological results].

Direct diode laser carotid (0.7-1.2 mm) end-to-end microanastomosis versus contro-lateral manual suture microanastomosis (CMA) were performed in 70 Wistar rats. The laser beam-wavelength 830 nm- was transmitted through a micromanipulator and provided a focused spot of 300 microns in diameter. After placement of three 10.0 Ethilon stitches for edge coaptation, the laser anastomosis was performed using laser shots (average 3) of 500 mW power, 4.5 s duration and 700 W/cm2 irradiance each. CMA was performed by six 10.0 stitches. Good vascular flow was confirmed by macroscopic controls, Doppler spectral analysis (n = 548) and digitalized angiography (n = 18) performed from day 0 to day 210. The patency rate (93%) as well as the complication rate (5/66) were similar in both series. Nevertheless light and scanning electron microscopy (n = 82) showed the morphological superiority of laser anastomosis: reendothelialization by day 3 and medial collagen restructuration by day 10 whilst after CMA, the arterial wall repair was delayed and the medial scar occupied by fibrotic tissue. The other advantages of the laser anastomosis were, shorter operating time minimizing organ ischemia (13 min versus 22 min), and slight endothelial trauma reducing thrombogenic risk. The technical advantages of diode laser were pointed out: miniaturization, no special maintenance and decreasing price of diodes.

Anastomosis, Surgical↗