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Biomedical subjects

M Barbara

Publications and source records attributed to M Barbara.

71 records · Page 4Linked to original sources
PubMed1982

Modification of two models of Arthus reaction in the rat by various drugs.

The action of several steroidal and non-steroidal antiinflammatory agents, immunosuppressives, and antirheumatics (levamisole, chloroquine, sodium aurothiopropanol sulphonate, D-penicillamine) was studied in two models of Arthus-passive reaction in the rat: paw oedema induced by an anti-ovalbumin serum, and pleurisy induced by an anti-bovine-albumin serum. The steroidal antiinflammatory agents reduced both types of reaction. In pleurisy, they acted on exudate and the number of neutrophils. The non-steroidal compounds were not active on the inflammatory reaction of the paw, but they decreased the volume of exudate in pleurisy without having any clear effect on cellular phenomena. The antirheumatics and immunosuppressives showed little or no action on the two models: of these only gold salt decreased Arthus reaction in the paw.

Animals↗
PubMedDate not supplied

Pharmacological studies on zymosan inflammation in rats and mice. 1: Zymosan-induced paw oedema in rats and mice.

Injections of zymosan in mouse and rat paws provoke inflammatory reactions, the kinetics of which are different. In both models, inflammation occurs at an early stage but oedema is maximal at 30 min in rat paw and 6 h in mouse paw. In this study the two reactions have been studied up to 6 h. The reduction of oedema by anti-H1 compounds, as well as by disodium cromoglycate, proves the active role played by histamine in rat paw oedema. In mouse its role appears to be minor or non-existent. Serotonin seems to be clearly implicated in the early stages of the oedema in mouse, somewhat less in rat. In the two species, non-steroidal anti-inflammatory compounds only reduce the 4-6 h phase. BW755C and phenidone reduce the early and late phase of paw oedema in both species, with the exception of phenidone which is inactive on the 4-6 h phase in the mouse. We can hypothesize that in the two species some leukotrienes seem to be implicated principally in the early phases, while derivatives of cyclooxygenase play a more important role in the late phases. Theophylline reduces inflammation in the two models, hydrocortisone acetate, however, is only active on the late phases. These results indicate that there are important differences in the participation of the various mediators studied in the two models.

Animals↗
PubMedDate not supplied

Pharmacological studies on zymosan inflammation in rats and mice. 2: Zymosan-induced pleurisy in rats.

Injection of zymosan in rat pleural cavity provokes an exudate which is already detectable at 15 min and which is maximum at 24 h. The leucocyte count (mostly neutrophils) increases at 2-4 h and is maximum at 48 h. In this paper the reaction has been studied up to 6 h. Evidence of histamine release, of mast cell degranulation and of reduction of the exudate by anti-H1 compounds, as well as by sodium cromoglycate, proves the active role played by histamine in the early stage of pleurisy. Serotonin (whose role was studied exclusively using antagonists) seems to have only a minor part in the early phase of the reaction. Some metabolites of arachidonic acid were determined in the pleural exudate at 1 h and 6 h. The concentration of leukotriene B4 was high at 1 h and decreased at 6 h. The thromboxane B2 level was already high at 1 h and was neatly augmented at 6 h while the amount of prostaglandin F1 alpha was high at both times. The non-steroidal anti-inflammatory substances studied all reduced the pleural exudate at 1 h but their activity then varied from each other at 6 h. Cyclooxygenase and lipoxygenase inhibitors (phenidone, BW755C) induced a reduction of the exudate at both times. Zymosan-induced pleurisy seemed thus to be an excellent model for the investigation of antiallergic and anti-inflammatory compounds active on histamine and cyclooxygenase and lipoxygenase pathways.

Animals↗
PubMedDate not supplied

Morphology of the endolymphatic duct and sac in the Mongolian gerbil.

A light microscopical study of the endolymphatic duct and sac of the Mongolian gerbil is presented. This animal model was studied because of its tendency to develop a condition of body fluid imbalance which may represent a hazard to the inner ear fluid environment. Particular stress is laid on the combination of the lack of an extraosseous endolymphatic sac and the presence of elastic tissue in the subepithelial space of the sac. These findings highlight the role of this structure for the regulation of the pressure within the inner ear. Lastly, a secretory process is proposed by which a homogeneous precipitate produced in the lumen of the sac can regulate volume and pressure changes.

Animals↗
PubMedDate not supplied

Action of tioxamast on various models of anaphylactic shock, hyperreactivity and bronchial inflammation in guinea-pigs.

Tioxamast, an anti-allergic compound inhibiting the release and synthesis of certain mediators of allergy and having no major antagonist effect towards such mediators, was experimented on various models of anaphylactic shock, hyperreactivity and bronchial inflammation in guinea-pigs. Tioxamast does not reduce passive pulmonary anaphylactic shocks induced in anaesthetized or conscious guinea-pigs by i.v. challenge of antigen. Likewise, the compound has no effect on systemic hyperreactivity towards i.v. histamine induced in anaesthetized guinea-pigs after a passive anaphylactic shock caused by i.v. challenge of antigen. On the other hand, tioxamast inhibits passive pulmonary anaphylactic shock induced in guinea-pigs by antigen aerosol in conscious guinea-pigs. Likewise, tioxamast decreases hyperreactivity to inhalation of histamine or carbamylcholine obtained after an active or passive anaphylactic shock by aerosol in conscious guinea-pigs. The oxamate derivative attenuates the increase in number of eosinophils and mononuclear cells obtained in the bronchoalveolar lavage fluid 24 hr after an active anaphylactic shock induced by aerosol. The anti-allergic activity of tioxamast on the various models carried out in guinea-pigs thus appears when these models are induced by a challenge of antigen or mediator by inhalation.

Aerosols↗
PubMedDate not supplied

[Histopathology of the internal ear: role of biopsy in ear neurosurgery].

Ultrastructural evaluation is a tool which provides useful information which can lead to understanding of the different physio-pathological mechanisms involved in various otological disorders. After a short review of the procedures presently available for histopathology of human temporal bones from cadavers and indication of their related problem, the authors define the pros and cons of intra-operative biopsies of the membranous structures of the inner ear. The different histopathological methods are presented which may be applied on each specimen along with some technical details which make their use feasible for any otoneurosurgical center. The different membranous inner ear structures are taken into consideration; structures which can be approached by different otoneurosurgical procedures. Emphasis is placed on some technical hints to minimize artifacts. Finally, a more continuous, widespread use of intra-operative biopsies is proposed in order to obtain a fairly large amount of specimens as this would contribute to elucidate the unresolved problems inherent to many otological disorders.

Biopsy↗
PubMedDate not supplied

[Comparative antiallergic and anti-inflammatory action of F1865, mepyramine maleate, desonide and disodium cromoglycate after cutaneous administration].

The actions of F 1865 (ethyl 4' methoxy 4 phenyl thiazolyl 2 oxamate), an inhibitor of the release of histamine from mast cell, desonide, a corticosteroid, mepyramine maleate, an anti-H1 antihistaminic, and disodium cromoglycate were compared after cutaneous application in various experimental models of allergy and inflammation. F 1865 decreased IgE- and IgG-dependent passive cutaneous anaphylaxis in rats at doses having no effect on histamine- and serotonin-induced capillary permeability. Disodium cromoglycate showed the same activity spectrum, but its action was only found after intradermal application. The reduction of cutaneous anaphylaxis by desonide was found parallel to its inhibition of histamine effects, and to a lesser extent of serotonin effects. In the case of mepyramine, the antiallergic effect may be explained by its antihistaminic action. Desonide was highly active on cantharidin-induced non-immune inflammation and on non-immune and delayed hypersensitivity reactions induced by picryl chloride in mouse ear. Although far less active than the corticosteroid, F 1865, mepyramine and disodium cromoglycate did reduce the three types of reactions in mice. This evidenced a part played by histamine in such inflammations. Then it is likely that the inhibition of histamine release by F 1865 plays an important part in the effect of the compound observed in the various inflammations studied. However we cannot exclude actions against other mediators involved in these reactions.

Administration, Topical↗
PubMedDate not supplied

[Cytologic findings on chronic inflammatory disease of the vocal folds].

The usefulness of cytologic diagnosis in laryngeal pathology is still controversial, also in the cytopathologist's opinion. A sampling procedure such as routine cytodiagnosis can be considered useful for both diagnosis and treatment of non-surgically related laryngeal diseases. This study was designed in order to demonstrate how cytodiagnosis can be useful in etiologic and pathogenetic diagnosis of chronic non-specific inflammatory diseases of the vocal folds. Cytologic sampling was carried out on brushing material of simple and hyperplastic laryngeal inflammations and on normal vocarfolds which were used as control. Through cytologic examination it was possible to evidence specific morphological findings which allowed differentiation of not only healthy from diseased vocal cords, but also hyperplastic from simple inflammatory processes. Moreover, the high incidence of goblet cells and cylindric squamous metaplasia in hyperplastic corditis, as well as the frequent presence of fungal involvement in the simple forms, prompted the Authors to hypothesize pathogenetic mechanisms as well as progression inducing factors of the pathologies in question.

Carcinoid Tumor↗
PubMedDate not supplied

[The surgery of the endolymphatic sac: a conservative or destructive procedure?].

A detailed analysis of different aspects relative to endolymphatic sac surgery employed as conservative surgical treatment in Menière's disease is presented. The presumed basic principles for this type of surgery, which have led several otologists to adopt this procedure in the therapeutical protocol followed in Menière's disease, are discussed along with the good symptomatological results obtained. Particular emphasis is put on the multiple functions which have been attributed to the endolymphatic sac in the functional dynamics of the entire inner ear environment. Among these functions, relevance is given to the secretory activity, which is presumed to be triggered by endolymphatic dysbarisms, which implies that macromolecules that are able to interact with fluid metabolism (glycosaminoglycans) might flow into the luminal endolymphatic space, a phenomenon which may well open new perspectives for the pathogenesis and treatment of Menière's disease. On the grounds of these premises, the conservative aspect of endolymphatic sac surgery, along with its mechanism of action, is reassessed.

Ear, Inner↗
PubMedDate not supplied

[Anesthesiological methods in acoustic neuroma surgery using the translabyrinthine approach].

Removal of acoustic neuromas may often imply anesthesiological as well as surgical problems, especially in the case of large tumors (> 3 cm) which may have come into contact with vital neighbouring structures (brain stem, cerebellum). In this paper the use of two different anesthesiological methods during the translabyrinthine approach is analyzed and discussed in the light of the different needs in this type of surgery. More specifically, anesthesia maintenance was assured by constant infusion of either Propofol (4 mg/kg/h) or Isoflurane (1-1.5%). Withdrawal of curarization was also planned in order to allow the surgeon to take advantage of routine intraoperative facial nerve monitoring. Arterial pressure, CO2 and O2 were assessed at prefixed phases of the operation. Both anesthesiologic methods proved to be satisfactory during the entire surgical procedure. During dissection of the tumoral capsule, an increased heart rate (7% of the initial value) was noticed, whilst in only three patients (with tumors larger than 3.5 cm) a severe bradycardia, which did not respond to Atropine administration and which subsided spontaneously during temporary suspension of surgical manoeuvres, occurred. After this preliminary experience, the Authors believe that both techniques could have a major role in translabyrinthine acoustic tumor surgery and auspicate their further application.

Adult↗