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Biomedical subjects

N Ionescu

Publications and source records attributed to N Ionescu.

114 records · Page 7Linked to original sources
PubMedDate not supplied

Congenital ichthyosiform erythroderma (C.I.E.)--ultrastructural evidences of abnormal stratum corneum retention.

Congenital ichthyosiform erythroderma (C.I.E.) is a skin disorder which has been considered as a hyperkinetic hyperkeratosis. This study was performed in order to demonstrate that C.I.E. pathogenesis includes both basal cell hyperplasia and abnormal stratum corneum retention. Electron microscopic studies were carried out on 5 cases of C.I.E., clinically and histopathologically diagnosed. The following pathological changes were found in stratum corneum and stratum granulosum: persistence of desmosomes in outer layers of stratum corneum, increased volume of intercorneocyte material, loss of lamellar pattern of Odland bodies, important variability in size and shape of keratohyaline granules, abnormal aggregation of tonofilaments. These constitute ultrastructural evidences of abnormal stratum corneum retention in C.I.E. pathogenesis.

Cytoplasm↗
PubMedDate not supplied

Some aspects of oxidative metabolism in human endometrium after long time of applying the intrauterine contraceptive device.

The paper intends to study the variation of oxidative metabolism of human endometrium (all the components) after applying the intrauterine contraceptive device for a long period of time. The results of the study show that modifications "in situ" of the oxidative enzymes vary according to the: type of the enzymes (NADH2-cytochrome-c-reductase, Lactatdehydrogenase), the hormonal cyclic stage (proliferative phase, or luteal phase), epithelial or connective tissue structures, time of resting the intrauterine contraceptive device (DIU) in uterus.

Endometrium↗
PubMedDate not supplied

Study on the normal and pathologic structures of the hard dental tissues using the scanning electron microscope.

The recent use in biology of the Scanning Electron Microscope allows a new vision of the sample, completing the previous ones: the Optical Microscope (OM) and the Conventional Electron Microscope--CEM. The object is observed in space, in a direct way and, due to a system of variable sizes, the passage from a general image to the detailed tissue and cell study is permitted. The outer enamel surface with its perikymaties, its flaws and its changes caused by usage as well as by the internal enamel structure on the fractured area have been studied. On the occlusal surface of the decayed teeth, focal holes have been found; they resulted probably from creation disturbances due to some amelogenetic disorders that damage the ameloblast, matrix creation or its mineralization. These lacunar flaws are the favourite zones for the microbe plate accumulation and propitious to carious lesions initiation. The same clinical aspect, of profound enamel creation defects with an anfractuous crevass network aspect, having a variable expansion and depth, can be found in microscope with some healthy teeth. Regrouping in fascicles of the different prism directions can be found after structural analysis of the prismatic morphology of the parodontotic tooth enamel. An aspect of a more compact structure is thus obtained sectionally. This explains partially the increased resistance to decay of these teeth. In a comparative study of the fractioned area of some decayed and ruined temporary teeth, significant differences in prism arrangement can be found. The decayed teeth show expansions of the intraprismatic spaces, accusing reduced resistance against decay attack.

Dental Enamel↗
PubMedDate not supplied

Disseminated Langerhans cell histiocytosis: a case report with a light microscopic and ultrastructural study.

A case of disseminated Langerhans cell histiocytosis (L.C.H.) in a 9 month-old boy is reported. The clinical picture was characterized by severe multivisceral involvement with cutaneous and bone lesions. Histological examination of the skin biopsy revealed diffuse infiltration of large mononucleated histiocytes admixed with a small number of inflammatory cells. Ultrastructural examination confirmed the Langerhans cell (L.C.) phenotype by showing intracytoplasmic Birbeck granules in the proliferating histiocytes. We report the histological and ultrastructural characteristics of our case and review the diagnostic features of L.C.H. in the light of the criteria established by the Writing Group of the Histiocytic Society in 1987.

Histiocytosis, Langerhans-Cell↗
PubMedDate not supplied

[The repair of voluminous postoperative abdominal wall defects with synthetic mesh].

Important postoperative abdominal wall defects, especially recurrent or multirecidivated ones, are raising multiple problems to the surgeon. We are presenting a homogeneous trial of 209 patients with such lesions, in which the abdominal wall repair was made with different kind of synthetic materials, with good results. In a single case the mesh was rejected, because a silent quiescent infection. In three patients undergoing iterative abdominal operations for other diseases we performed optical and electronic microscopical studies showing out that the material integration was done by normal biological reaction. This provides the materials' tolerability and a normal reaction of the organism.

Abdominal Muscles↗