PubMed Health⌕ Search

Biomedical subjects

A N Delrio

Publications and source records attributed to A N Delrio.

At least 19 recordsLinked to original sources
PubMed1996

In vitro effects of some differentiation inductors in metaplastic epithelium of the human nasal cavity.

The alterations in the mucociliary unit in the course of chronic inflammation of the upper respiratory tract correspond to morphologic anomalies of the respiratory epithelium and induce cuboidal and squamous metaplasia. While the squamous pattern is most probably irreversible, it is still not clear whether it is possible to restore ciliogenesis in cuboidal metaplasia. In the present study, the action of different inductors of differentiation was evaluated in vitro in isolated cells and explants from human nasal metaplastic epithelium. Polar/apolar compounds induced secretory activity, whereas retinoic acid was able to induce ciliogenesis in some cases. Therefore, the cuboidal metaplastic condition appears to be reversible, and two distinct pathways of differentiation, secretory and ciliogenetic, are identifiable.

Acetamides↗
PubMed1992

[The shape of the nasopharynx in youth: statistical study].

The particular shape of the nasopharynx in the child can influence morphology and physiopathologic behaviour of the mucosa. In such a perspective, it appeared interesting to evaluate the kind and the entity of its variations by means of nuclear magnetic resonance (NMR) in 50 patients (age range: 2 months-16 years). The results show that the nasopharyngeal shape (represented either by bending radius and shape factor) varies in a statistically significant way during the considered age range, while the dimension of the pharyngeal tonsil remains constant in the studied cases. The statistically significant shape variation of the tonsil appears, so, related to its involvement in the shape variation of the whole nasopharynx.

Adolescent↗
PubMed1992

Structural and ultrastructural pattern of the embryonic and early foetal human liver.

With the aim of stressing the main steps which characterize the early development of the human foetal liver, fragments of hepatic buds of 7-12 weeks of pregnancy have been processed for light and scanning electron microscopy; Vial and Porter technique for isolated cells has been utilized too. The obtained results can be summarized as follows. At the 7th-8th weeks the hepatocytes show a globose shape, their surface is furnished with scattered and irregular evaginations and they are arranged in loose and narrow ribbons, separated by vascular spaces; the hepatocytes are tightly connected with haemopoietic cells, usually furnished with hyperchromatic nuclei. On the other hand, the hepatic parenchyma shows a compact pattern at the 11th-12th weeks. The hepatocytes have acquired a polyhydric shape and their faces are usually interlocked with the plasmatic membrane of the adjoining elements than in three fields: (a) the face projecting to the vascular walls with which they are going to form the Disse spaces; (b) the opposite side in which the membranes of neighbouring cells often appear spaced to line the primitive biliary canaliculi; and (c) the areas in which hemispheric and deep hollows of the hepatocyte surface hold haemopoietic elements. The obtained results demonstrate that the developing hepatic buds undergo deep structural changes, at level of the parenchyma and vascular system, in the studied period.

Fetus↗
PubMed1992

[Structural organization of the menisci of the human knee: scanning electron microscopy study].

The structure of the meniscus of the knee joint was studied in 10 human subjects after meniscectomy for acute trauma. The specimens were studied by scanning electron microscopy after cryofracture. Collagen fibres are arranged in two layers: a thin superficial zone with radially oriented fibres and a deep zone with circumferentially oriented ones. Deep fibres are surrounded by oblique fascicules. The cells are rare and oval-shaped. The observations enhance the hypothesis that the meniscus of the knee joint is not a real fibrocartilage.

Adult↗
PubMed1991

[Morphologic scanning electron microscopic study of quantitative variations in the endosseous diaphyseal surface in normal and osteoporotic rats].

An ultrastructure study (S.E.M.) was performed on adult albino rats of the age, sex, and weight in order to assess the qualitative and quantitative variations in the endosteal diaphyseal surface of limbs relieved of mechanical stresses by means of prolonged cast immobilization. The final results confirmed the primary role played by osteoclasts and vascular bone channels, the latter of which open into the diaphysis, during resorption of compact diaphyseal bone, which occurs to the detriment of the bone surfaces in deposition and at rest.

Animals↗
PubMed1990

[Osteoid osteoma. A scanning electron microscopic study].

The mineralization process of the osteoid osteoma, after removal of the organic matrix from the specimens by treatment with 6% sodium hypochlorite, has been studied by SEM. The process was characterized by calcified nodules or calcospherites, variable in size from 0,1 to 2 microns, embedded among randomly oriented collagen bundles, which delimited trabeculae of sponge primary bone. Numerous osteocytic lacunae, in various degrees of development, in the mineralizing front were present. The ultrastructural feature of the mineralization in osteoid osteoma reflected a pattern of nodular and collagenous calcification, essentially similar to primary calcification, characteristic of rapidly developing woven bone.

Adolescent↗
PubMed1990

[Osteosis due to primary hyperparathyroidism. The SEM ultrastructural features of the periosteal and endosteal surfaces].

The study of four cases of osteosis caused by primary hyperparathyroidism, tree female and one male, which have undergone surgery for pathological fractures in met-epiphysis bone, allows to analyze with the help of scanning electron microscope modifications occurring in periosteal and endosteal bone matrix. The periosteal surface appears abundantly furrowed by large and deep canals, irregularly joined together. Areas of resorption, these at rest and these of osteodeposition are distributed in changeable but regular way. The bone turnover of endosteal side is particularly accentuated. This surface contains the bone trabeculae residuals and is widely marked by deep Howship's lacunae, which show intense osteoclastic activity. It seem that osteocytes cells participate actively in the process of osteolysis, widening the lacunae and small canals which appear to be surrounded by calcospherites arranged in irregular way. Osteogenetic activity, with large areas of deposition, is very intense, as a defence attempt against osteolytic resorption process.

Adult↗
PubMed1990

Ultrastructural characteristics of the human synoviocytes.

The purpose of this study was to identify, by the scanning electron microscopy, the behaviour of the different cell types in the normal human synovial intima, in order to obtain information useful for interpreting pathological changes in the synovium. Our observations revealed that, in numerous areas of the synovial membrane (adipose or fibrous type), the synoviocytes were dispersed and the intercellular matrix, covered only by the cytoplasmic processes of cells deeply located, was in direct contact with the joint cavity. In the areolar type of the synovium the synoviocytes were more numerous; they tended to concentrate to give the appearance of a continuous tissue; but between the cells very large intercellular spaces were usually present. In this latter membrane type we identified the two main cellular types of the synoviocytes: A and B. B-synoviocytes were the predominant cell type of the synovium. These cells were characterized by long cytoplasmic processes, perpendicularly directed towards the joint cavity. Both the cellular body and the cytoplasmic processes were covered by small blebs and vesicles of various size. The A-synoviocytes were a small minority, rarely dispersed between the B-synoviocytes. They were characterized by numerous membrane infoldings which delimited intracellular canaliculi of various depth. Our ultrastructural observations demonstrated that, in normal conditions, the B-synoviocyte must be considered as a constitutive element which characterized the synovial intima, responsible for the specific structure of the interstitial tissue and for the regulation of the composition of the synovial fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMedDate not supplied

Distribution and characteristics of synoviocytes in the rabbit knee joint: a scanning/transmission electron microscopic study.

The distribution and the characteristics of A and B synoviocytes were investigated using scanning and transmission electron microscopy in the study of the three types of synovial membranes (fibrous, areolar, adipose) of the rabbit knee joint. The scanning electron microscope showed that the B-synoviocytes had dendritic processes and were separated by wide spaces in the fibrous synovium. The areolar synovium was covered by numerous B-synoviocytes of fibroblastoid-shape. The B-synoviocytes of the adipose synovium were characterized by short cytoplasmic processes. The transmission electron microscope revealed that the B-cells showed signs of intense synthetic activity such as the presence of an evident rough endoplasmic reticulum, the Golgi apparatus and many peripheric vesicles. Our study also revealed that cells with morphological and ultrastructural characteristics of macrophages, the so-called A-synoviocytes, were present in the areolar membrane. We concluded that B-synoviocytes can show variable shape under normal conditions: in particular, dendritic morphology seems to be a normal characteristic of the synoviocytes of the fibrous membrane. Moreover, our results demonstrate that A and B synoviocytes are ultrastructurally and morphologically distinct cells and that each type has different functions.

Animals↗
PubMedDate not supplied

On a particular method of isolation of the human placenta trophoblastic cells.

With the purpose of demonstrating the presence of different types of cells in the syncytial and cytotrophoblast of the human placenta, a new technique of cell isolation was performed by utilizing a light enzymatic digestion and a separation on density gradients. Normal human placentas of the first trimester of pregnancy have been studied. After an accurate and light washing in saline and anticoagulant substances, whole villi have been incubated in a trypsin solution for various periods of time at 40 degrees C in a thermostatic stirrer. Detached cells have been collected, rinsed and separated by means of different density gradients of Percoll (d = 1.038 and 1.080). Three cellular layers have been collected and processed for the studies at light and electron microscopy. The first layer was mostly composed by multinucleated elements with a morphological pattern closely related to the histological characteristics of the syncytiotrophoblast; the second fraction was composed by mononucleated elements with the structural findings of the Langhans' cells; the third layer was represented almost exclusively by blood cells. The obtained results demonstrated the high utility and accuracy of the suggested method of cell isolation.

Cell Fusion↗
PubMedDate not supplied

[3-dimensional characterization of the synoviocytes of the human synovial intima].

The intimal synovial surface in normal conditions, using a scanning electron microscope, has been studied. The three synovial membrane types are clearly recognizable: fibrous (Fig. 8), adipose (Figs. 9 and 10) and areolar (Figs. 1 and 2); but only in the areolar type, the characterization of the main two cellular types: synoviocytes B and A, is possible. Synoviocyte B represents the constitutive element which characterizes the synovial intima; it has a cellular body of irregular shape and long cytoplasmic processes directed towards the joint cavity (Figs. 3, 4 and 5). The cellular body and the cytoplasmic processes are covered by small blebs (Fig. 6). and similar vesicles, probably of the same cellular origin, are scattered throughout the extracellular matrix. These cells are likely responsible for the specific structure of the interstitial tissue adapted to the exchanges and to the regulation of the composition of the synovial fluid (Okada et. al. 1981; Linck and Porte, 1978, 1981). Synoviocyte A is a small minority; it has many long and irregular membrane infoldings which define a complicated system of intracellular canaliculi of various depth (Fig. 7). The ultrastructural characteristics of their surface and the peculiarity of their organelle apparatus, described by other AA. (Fell et. al., 1976), demonstrate that these elements carry out a macrophagic function. The clear majority of the synoviocytes B in the intimal surface suggests that in normal conditions, the synthesizing processes prevail over the phagocytosis ones.

Adult↗
PubMedDate not supplied

The sertolian epithelium in the testis of men affected by 'Sertoli-cell-only syndrome'.

Because of the architectural complexity of the seminiferous epithelium, the Sertoli cell is extremely difficult to study. The individual cellular constituents of the tubular wall are intimately associated with one another; especially Sertoli cells and germinal cells are tightly connected. As implied by the name, Sertoli-cell-only syndrome (SCOS) is characterized by the presence of only Sertoli cells in the seminiferous tubule. The absence of germinal cells makes this condition ideal for the morphological study of Sertoli cell. Testicular biopsy specimens of subjects affected by SCOS were studied under light and electron microscopy. The Sertoli cells appeared to be morphologically normal, except for their shape, that appears to be columnar as result of the complete absence of the germinal cells. The cellular outlines were irregular, particularly at the base, but the cytoplasm contained normal organelles and inclusions. The presence of both pale and dark elements was evident. These differences in staining reflect the variability in concentration of glycogen particles and intermediate microfilaments in the cytoplasm. In spite of these differences between Sertoli cells in SCOS and those in normal subjects, SCOS represents a satisfactory model for the morphological and functional analysis of the Sertoli cells.

Actin Cytoskeleton↗