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Biomedical subjects

B Foliguet

Publications and source records attributed to B Foliguet.

72 records · Page 4Linked to original sources
PubMed1977

[Pulmonary complications after extracorporeal circulation. ECC lung syndrome].

Pulmonary complications after cardiac surgery under extracorporeal circulation remain frequent and sometimes grave, in spite of the great progress which has been made over the past 20 years in the methods of cardiorespiratory assistance. The authors analyse the clinical and radiological repercussions of perfusion on the lung, in 40 patients operated under ECC for coronary revascularisation. The simutaneous study of the arterial, and mixed venous blood gasses and of the alveolar gases, in 20 of these patients showed the constant occurrence of a shunt syndrome, without alveolar hypoventilation or disorders in peripheral circulatory flow. Ventilatory alcalosis, hypocapnia, hypoxemia and the rise in the alveolar arterial oxygen gradient is increased during the second post-operative day. Among the variables studied (duration of ECC, degree of hypothermia, duration of the intervention, duration of anesthesia, pleurotomy) only the latter intervened in a statistically significant manner in this study, in the increase in hypoxemia. 46 pulmonary biopsies carried out before and after ECC in 23 coronary patients were examined with the electron microscope. The initial alveolar involvement affects the septal microcirculation with signs of an increase in capillary permeability leading to an interstitial and epithelial destruction. The use of a membrane oxygenator prevents some of the alveolar lesions, as has been proved by the study of five pulmonary biopsies carried out in dogs submitted to ECC of long duration. Catherterization of the pulmonary artery carried out in 35 patients by means of a SWAN-GANZ catheter, before the intervention enabled supervision of the degree of importance and speed of the hemodynamic variations in the pulmonary circulation during the different phases of ECC (during the phase of ventricular fibrillation). The rise in the flow of left output can lead to the occurrence of negative pulmonary intravascular pressures which can be prejudicial for capillary trophicity. The syndrome of "ECC lung", a veritable "induced post-agressive lung" must be placed in the group of refractory hypoxemia of which it represents one of the most typical pictures.

Alkalosis, Respiratory↗
PubMed1975

[Pulmonary edema due to shock, fat embolism, disseminated intravascular coagulation and post extracorporeal circulation].

The appearance of lesional edema in the region of the alveolar wall constitues the initial phenomenon of involvement of the pulmonary parenchyma during shock lung, fat embolism, DIC and post perfusion lung syndrome. The alveolar septum reacts in a monomorphous manner to these various agressions, although the responsible physiopathological factors are numerous and varied. The lung in E.C.C. represents a vertiable experimental post-agressive lung. It has been studied in man from the clinical, radiological, hemodynamic and anatomopathological standpoints. The modifications found enable one to better understand the etiological factors intervening in the other post-agressive lungs.

Adult↗
PubMed1975

[Oxygen toxicity for pulmonary parenchyma. Ultrastructural study by electron microscopy. Physiopathologic data].

The lungs of rats submitted to 24, 36, 48 and 72 hours of pure normobaric oxygen were examined by means of the scanning microscope. The images obtained give a dynamic aspect of the changes in the lesions with two distinct phases: a phase of reactivity at 48 hours, marked by the development of hyperactivity of the granular pneumocytes, a phase of destruction characterised by considerable changes in the alveolar epithelium and filling in of the alveolar lumen with various debris. From these morphological findings, different physio-pathological factors are discussed: the role of the increase in PaO2, the protection provided by the increase in the gradient (A - a) DO2, cerebral and adrenal medullary involvement especially in hypoxemic subjects.

Animals↗
PubMedDate not supplied

Evolution of the local calcium content around irradiated beta-tricalcium phosphate ceramic implants: in vivo study in the rabbit.

To evaluate whether dissolved calcium from tricalcium phosphate implants contributes to osseous wound healing in bone defects, the authors used nuclear radioactivated materials. Six months after irradiation, the calcium was still radioactive. Samples of the material were prepared and placed in rabbit condyles for 1, 3 and 9 months. Over time the condyles were retrieved and treated for histology or radiocounting. Measurements of the radioactivity of the slices and histomorphometry of the implants and surrounding tissues were performed. The authors observed that the radioactivity decreased regularly. Connective tissue had penetrated the pores and totally invaded the implants, first at the periphery of the implants, then inside the pores. Comparison of the results of radioactivity and histomorphometry suggest that part of the calcium from the implants was re-used specifically in the new osseous tissue.

Animals↗
PubMedDate not supplied

Expression of IL-2alpha and IL-2beta receptors on the membrane surface of human sperm.

Cytokines are secreted proteins that act as local immunological mediators. Increased seminal cytokine concentrations are associated with fertility problems. The purpose of the present study was to investigate the presence of IL-2alpha, and IL-2beta receptors on fresh and isolated sperm by flow cytometry and transmission electron microscopy. Twenty sperm samples from oligospermic men were incubated with CD25, a mouse monoclonal antibody specific for IL-2alpha-chain receptor, and CD122, a mouse monoclonal antibody specific for IL-2beta-chain receptor. The strong initial fluorescence intensity and, subsequently, a labeling index yielded by CD25 and CD122 decreased in sperm centrifuged on a Percoll gradient (p < .05). The expression of CD25 and CD122 correlated negatively with fresh sperm concentration, but in sperm centrifuged on a Percoll gradient there was no correlation. Labeling with CD25 and CD122 antibody was evident on the head and the middle piece in fresh sperm, while in sperm centrifuged on a Percoll gradient a weak labeling was observed only on the principal piece. The authors have identified and localized cytokine receptors on human sperm for the first time. Cytokine receptors may be involved in the regulation of pathophysiological events in sperm cell functions and male infertility. The exact pathway involved in modulation of these receptors requires further investigation. These results contribute to the understanding of cytokine-sperm relationships.

Flow Cytometry↗
PubMedDate not supplied

Lectin-binding sites on human sperm during acrosome reaction: modifications judged by electron microscopy/flow cytometry.

Biochemical surface modifications occur during the capacitation and acrosome reaction of human sperm and among those, variations in the expression of carbohydrates moieties. A sequential study was performed with electronic microscopy and flow cytometry techniques, where the binding of 4 lectins was assessed on normal human sperm samples during in vitro induction of the acrosome reaction with calcium ionophore A-23187. Triticum vulgaris agglutinin (WGA) was shown to bind strongly the whole surface of sperm before induction of the acrosome reaction, and in lesser amounts after incubation with calcium ionophore. Arachis hypogea agglutinin (PNA) and mostly Concanavalia ensiformis agglutinin (Con-A) and Ulex europaeus agglutinin (UEA-1) binding evolved in an opposite pattern with an increase of the labeling parallel to that of GB24 antibody binding. Electron microscopy showed that the fluorescence patterns observed correlated with increased access to the inner membrane of the acrosome. This was significant 60 min after the induction of acrosome reaction. Lectin binding could be a useful tool to examine the ability of sperm samples to undergo the acrosome reaction.

Acrosome↗
PubMedDate not supplied

Centrifugation on Percoll gradient enhances fluorescent lectin binding on human sperm: a flow cytometric analysis.

Centrifugation on a Percoll gradient is commonly used to enrich sperm preparations in mobile forms prior to in vitro fertilization attempts. It has been suggested that this method also induces the capacitation of sperm, a step preceding the acrosomal reaction allowing egg fertilization. The modifications of the acrosomal membrane involved in these physiological events likely include alterations of glycosylation patterns. This hypothesis was investigated by comparing the membrane binding of 15 fluorescein-conjugated lectins on 60 samples of sperm, before and after Percoll centrifugation. The numbers of labeled sperm and their mean fluorescence intensity, recorded in flow cytometry, significantly increased for 10 and 14 of the 15 lectins tested. Microscopic examination of the labeled sperm showed that the acrosome and equatorial plates were more often labeled after Percoll centrifugation, confirming the hypothesis that this method modifies the glycosylation pattern of structures important for egg fertilization.

Centrifugation, Density Gradient↗
PubMedDate not supplied

Apical structure of human respiratory cilia.

The apical structure of human respiratory cilia was studied using thin and thick sectioning techniques. The distal end of the mature cilium is narrowed and presents dense material and a crown-shaped glycocalyx. The crown is composed of three to seven bristles, having a mean length of 31 nm and showing a periodic structure. The capping structure of the apical part of human respiratory cilia is composed of a plate and an electron-dense cap tightly bound to the central and to each of the nine peripheral A microtubules. Lateral spokes link the peripheral microtubules to the internal ciliary plasma membrane and dense filaments radiate from the dense cap to the ciliary crown. These ciliary apical structures may be involved in several functions associated with microtubule assembly as well as ciliary movement and mucociliary transport.

Adolescent↗
PubMedDate not supplied

[Myofibromatosis in children. Histopathologic and ultrastructural study of a localized form with a spontaneously regressive course].

Report of a case of the localized form of infantile myofibromatosis, in a three-month-old boy with a brachial mass and osteolytic lesion of the adjacent humerus at radiographic examination. Diagnosis is made on the histopathological features of the lesion at biopsy. Ultrastructurally, the tumor cells have myofibroblastic differentiations. Evolution is regressive without any treatment. The anatomical, clinical, pathological, ultrastructural and evolutive features are discussed.

Arm↗
PubMedDate not supplied

[Experimental chronic paraquat poisoning. Functional and histopathological pulmonary changes].

An experimental model of pulmonary interstitial fibrosis was attempted in beagle dogs by intravenous administration of weak doses of paraquat. After various trials, the final protocol involved the intravenous injection of 2 mg/kg repeated every eight days for three weeks, and then every 15 days. On the 70th day, areas of localized interstitial fibrosis were observed (less than 10% of the surface of the tissue sections) in an otherwise healthy parenchyma. There was no marked hepatic or renal lesion. The evolution of the inflammatory and toxic processes was followed by the changes: 1) in the animal's weight (drop in weight after the injection of paraquat), 2) in blood gases (essentially drop in PaO2 and in SaO2), 3) in ventilation and respiratory exchanges (increase of VE and ventilatory frequency, decrease of Duco2), and 4) in static pulmonary compliance (distinct fall after injection). All these modifications showed a close relationship to the pattern of the paraquat injections. They receded 15 days after the last injection and reappeared after a new injection. The pulmonary hemodynamic study carried out only at the beginning of the experiment and before the animal was killed showed only a few anomalies (reduction of the average pressure of the right atrium).

Animals↗
PubMedDate not supplied

[The pores of Kohn in pulmonary alveoli].

The pores of Kohn are apertures in the alveolar septum, which allow the communication of two adjacent alveoli. Their existence has been most disputed, but was lastly supported in man and adult mammalians by observations from electron microscopy. Located between the meshes of the capillary network, these alveolar apertures are circular or oval, and are bordered by extensions of type I pneumocytes. Type II pneumocytes are often located close to the pores of Kohn. The presence of two near apertures gives a "double-barrelled gun" aspect, frequently observed in the old animal. The specific connections of the pore of Kohn with the septal components, particularly by the myofibroblasts, are analysed. The quantification of the pores of Kohn in various species shows great variations according to the fixation technique, animals age and site of alveoli in the lung and the lobules. The size of these apertures also depends on species, varying from 0.8 to 15 micrograms. Histogenesis of these apertures is still poorly understood and various processes can be evoked. Ventilation, which differs according to the site of the alveoli in the lung, is a determinant factor, proved by the great number of pores of Kohn in the hyperventilated areas. The role of the macrophages (synthesis and excretion of proteases and lipases) is also discussed. The formation of pores of Kohn is linked with renewing and dehiscence of alveolar epithelial cells. The role of alveolar pores in collateral ventilation seems relatively weak in the physiological state, whereas it is certain in lung pathology, contributing to the propagation of bacterial infections in the adult and to changes of local ventilatory conditions in atelectasis and asthmatic bronchoconstriction. The alveolar apertures can explain the specific propagation of some epitheliotropical peripheral cancers (bronchiolo-alveolar carcinoma). The pore of Kohn is one of the first signs of parenchymatous senescence of the pulmonary alveolus; its part in the appearance and extension of emphysematous disorders is also discussed.

Adult↗