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Biomedical subjects

G Familiari

Publications and source records attributed to G Familiari.

At least 37 records · Page 2Linked to original sources
PubMed1993

Ultrastructure of human ovarian primordial follicles after combination chemotherapy for Hodgkin's disease.

Ovarian damage, with consequent permanent infertility, is one of the more common side-effects which occurs during chemotherapeutic treatment of patients affected by Hodgkin's disease. This damage is morphologically represented by a marked loss of primordial and primary follicles. The administration of contraceptive drugs before starting chemotherapy enhances survival of a greater number of ovarian follicles, as revealed by morphometric analyses, nevertheless, total ovarian protection is not assured. This study evaluated the number and the morphology of ovarian follicles, by means of transmission electron microscopy, in patients with Hodgkin's disease treated with multi-drug chemotherapeutic protocols following the administration of medroxyprogesterone acetate. Ovarian biopsies were performed prior to any pharmacological treatment, after medroxyprogesterone therapy, and after this therapy plus chemotherapy. Particular attention was given to the ultrastructure of primordial follicles. After morphometric evaluation, primordial follicles were numerous in controls and medroxyprogesterone therapy (28.55 +/- 6.59/mm3 of ovarian cortex). After chemotherapy and medroxyprogesterone acetate, the number of follicles was slightly reduced (19.37 +/- 3.41/mm3 of ovarian cortex) in contrast to the dramatic loss usually observed when protection is not given, although more follicles were atretic. Medroxyprogesterone may protect follicles only from acute, toxic effects of chemotherapy, which dramatically reduce their number and lead to sterility. Nevertheless, the quality of follicles is still impaired, and many undergo atresia, resulting in a shortened fertility period.

Adult↗
PubMed1993

Microvasculature of growing and atretic follicles in the rabbit ovary: a SEM study of corrosion casts.

Rabbit ovarian microvasculature, with particular regard to developing and atretic follicles, was studied by scanning electron microscopy (SEM) of vascular corrosion casts. The microvascular network of the follicles was arranged in typical round plexuses of varying shape and size. Four different morphological types of vascular plexuses supplied the follicles: Type 1 (100-250 microns in diameter) consisted of a simple net of thin capillaries that delimited a small empty central cavity. Type 2 (diameter > 250 microns) consisted of a multilayered capillary wall delimiting a large empty central cavity. This wall presented an inner layer made of uniformly distributed dilated and tortuous capillaries with numerous angiogenetic sprouts. Type 3 (diameter of 100-300 microns) lacked the central cavity and comprised randomly arranged thin capillaries. Type 4 (diameter > 250 microns) consisted of a multilayered capillary wall delimiting a central cavity. Its inner layer was made of capillaries not homogeneous in size and course (thin in some areas, sinusoidal in others, sometimes highly dilated). In addition, the wall showed large interruptions (avascular areas) and focal invasion of the central cavity by newly formed vessels. Types 1 and 2 showed the gradual transformation of thin capillaries into sinusoids as has been demonstrated in evolutive follicles. Types 3 and 4, described here for the first time, probably represent the vascular supply to atretic follicles. In particular, Type 3 supplied follicles undergoing obliterating atretic degeneration, whereas Type 4 supplied atretic follicles with hypertrophy of the theca layer. In fact, follicular atresia is a pleiomorphic phenomenon which ends in a regression of the follicles (obliterant atresia), but which may induce a temporary follicular hyperactivation (luteinizing atresia). These changes in the microvasculature prelude the formation of the so called "interstitial gland of the ovary". Furthermore, these data prove that: 1) both thecal capillary vasodilatation and angiogenetic processes basically support the gradual increase of ovarian blood flow during follicle growth; 2) microvascular changes of atretic follicles are possibly related to a type of inflammatory reaction since they seem to be a consequential rather than primary cause of atresia.

Animals↗
PubMed1992

A technique for exposure of the glycoproteic matrix (zona pellucida and mucus) for scanning electron microscopy.

The fine structure of the zona pellucida (ZP) covering the oocyte and of the mucus covering the surface of the intestinal villi was investigated by using a new method employing ruthenium red (RR), saponin, and osmium-thiocarbohydrazide impregnation. The glycoproteic matrices both appeared constituted by thin filaments (ranging from 22 to 50 nm in thickness) anastomosed to form a very fine network. RR prevented the dissolution and/or alteration of glycoproteins and polyanionic carbohydrates induced by acqueous fixatives. Saponin was a detergent of the soluble proteins. Osmium-thiocarbohydrazide preserved the glycoproteic matrix filaments from the mechanical stress induced by dehydration and critical point drying and reduced filaments packing and shrinkage. The technical improvement was demonstrated by the following results: 1) a regular arrangement of the filaments network; 2) a thickness of mucus filaments smaller than that obtained with other methods of preparation; 3) a homogeneous thickness of ZP filaments. This method allowed a very detailed study of the fine structural organization of the ZP and intestinal mucus. Therefore, this technique can be useful for a better evaluation of the morphodynamic of these and other glycoproteic matrices.

Animals↗
PubMed1992

Human zona pellucida during in vitro fertilization: an ultrastructural study using saponin, ruthenium red, and osmium-thiocarbohydrazide.

The human zona pellucida (ZP) and its changes during in vitro fertilization in oocytes at different maturational stages and polypronuclear ova at one- to four-cells stages were studied by transmission electron microscopy (TEM) and correlative scanning electron microscopy (SEM). To define the microstructure of the ZP, its amorphous masking material was removed using a detergent (saponin), and its structural glycoproteins were stabilized with a cationic dye, ruthenium red, followed by osmium-thiocarbohydrazide treatment. These methods allowed in all samples the clear visualization of variously arranged networks of filaments composing the outer and inner surfaces of the ZP. These filaments were straight or curved, 0.1-0.4 microns in length and 10-14 nm thick as seen via TEM or 22-28 nm thick as seen via SEM (the difference in thickness was due to the presence of the metal coating for SEM). The filament arrangement was remarkably different between the inner and outer surfaces of the ZP and among the various stages studied. The filaments of the outer surface of the ZP were basically arranged in "large" and "tight" meshed networks. Mature oocytes and fertilized (polypronuclear) ova had a regular alternating pattern of wide and tight meshed networks of filaments. On the other hand, immature and atretic oocytes displayed almost exclusively a tight meshed network of filaments. The inner surface filaments of the ZP of unfertilized oocytes at any stage were arranged in repetitive structures characterized by numerous short and straight filaments anastomosing with each other and sometimes forming at the intersections small, rounded structures. After fertilization, the inner surface of the ZP displayed numerous areas where filaments fused together. Collectively, these data clearly reveal that oocyte maturation and fertilization in humans are accompanied by changes of ZP filaments arrangement, which may be relevant in the processes of binding, penetration, and selection of spermatozoa.

Actin Cytoskeleton↗
PubMed1992

Cellular and microvascular changes of the ovarian follicle during folliculogenesis: a scanning electron microscopic study.

In order to study the three-dimensional topographic arrangement of the oocyte and zona pellucida, follicular cells and follicle microvasculature, this study applied alkali maceration methods for tissue exposure, the ruthenium red-detergent method for the extracellular matrix visualization, and the vascular corrosion cast technique to rabbits, guinea-pigs and mice ovaries at different stages of follicular development. Macerated samples showed a gradual differentiation of the oocyte surface. This, in primordial follicles, appeared rather smooth, but, with the follicular development, displayed a gradual increase of blebs and microvilli. The latter widely covered the surface of oocytes contained in large or mature follicles. The outer surface of the zona pellucida showed numerous fenestrations, whereas the inner one was smooth. The ruthenium red-detergent method permitted a well detailed view of the filamentous texture of the zona pellucida. The three-dimensional distribution of the contacts between oocyte and neighbouring follicular cells was clearly evaluated in macerated samples. Follicular cells of primary follicles were characterized by their short cytoplasmic processes reaching the oocyte surface. In secondary follicles, these processes issued secondary processes. In larger follicles, the secondary processes of the corona cells were much longer and thinner, and took a tortuous course to reach the oocyte surface, which ran among the numerous oocyte microvilli. This microvillous arrangement greatly increases contact between the oocyte and corona cells, and suggests a coordinated reciprocal control of the activities of both cell types. These data also showed that the spongy and filamentous nature of the zona pellucida is closely dependent upon the temporal differentiation and enormous increase in number of follicular cell projections and their ramifications. Maceration revealed the theca cells surface. In smaller follicles these appeared as fusiform cells which resembled fibroblasts. In larger or mature follicles, many theca cells differentiated to possess morphological features of steroidogenic cells. In addition, these cells delimited a series of intercellular communicating lacunae, continuous with wide pericapillary spaces. The gradual differentiation of the follicle towards a structure having an endocrinal role was further emphasized in vascular corrosion casts. A simple microvascular net made of thin capillaries supplying primary follicles was seen to transform into an elaborate sinusoidal network made of thick permeable capillaries, supplying mature follicles.

Animals↗
PubMed1992

Scanning electron microscopy of the rabbit gallbladder mucosal microvasculature.

The arrangement of the microvasculature of the rabbit gallbladder was studied by means of scanning electron microscopy (SEM) of vascular corrosion casts and parallel uncorroded samples, together with correlated light microscopy (LM) observations. The outer layers of the gallbladder wall possess a coarse capillary network supplied by long and straight vessels which also give off numerous smaller twigs for the mucosal layer. Thin richly branched and anastomosing capillaries originate from the mucosal twigs. The mucosal capillaries are arranged in structures having a bowl-like configuration with the convexity facing towards the serosal layer, and the concavity corresponding to the epithelial lacunae seen by SEM of uncorroded samples. These structures were polygonal or irregularly rounded, and limited by vessels arranged in folds. The vessels running in these folds were capillaries and/or venules. The vascular folds corresponded to the epithelial folds demonstrated by SEM and LM of uncorroded samples.

Animals↗
PubMed1991

The ultrastructure of human cumulus-corona cells at the time of fertilization and early embryogenesis. A scanning and transmission electron microscopic study in an in vitro fertilization program.

We observed the ultrastructure of the cumulus-corona cells (CC cells) surrounding: 1) human preovulatory oocytes unfertilized after in vitro insemination and 2) in vitro-fertilized polypronuclear ova (PO) at the pronuclear stage (3 pronuclei) and during early cleavage, at the 3-8 cell stage (cleaving PO). All the samples were obtained from women who underwent pharmacological hormonal stimulation during in vitro-fertilization procedures. Both cell groups were composed of irregularly rounded CC cells, showing an oval nucleus with one or more reticular nucleoli. Spermatozoa in close contact with CC cells were also seen. Linear and annular gap junctions between neighbouring cells were present, particularly in Group 1. Lipid droplets were present in both groups, appearing slightly more numerous and electron-dense in Group 2. In Group 1, mitochondria were numerous, polymorphic, and provided with cristae varying from lamellar to tubular. In Group 2, mitochondria also showed polymorphism, with bacilliform organelles with tubular cristae being predominant. In both groups cisternae and associated vacuoles and vesicles belonging to the Golgi complex were scattered in the cytoplasm of CC cells. Similarly, tubular and vesicular profiles of smooth endoplasmic reticulum were abundant and uniformly distributed throughout the cytoplasm of CC cells of both groups. In contrast, the abundant rough endoplasmic reticulum in Group 1 was formed by parallel stacks of flattened cisternae, whereas it was less plentiful and not arranged in stacks in Group 2. The CC-cell surface appeared covered by numerous membrane expansions in both groups. The expansions in Group 1 were mainly composed of blebs of various sizes and a few short microvilli, whereas in Group 2 numerous microvilli covered the cell surface. These observations demonstrate that a gradual establishment and maintainance of a steroidosynthetic capability (luteinization) takes place in CC cells, particularly during and shortly after fertilization, as occurs contemporaneously in the granulosa cells of the postovulatory follicle. Our results may be considered as ultrastructural confirmation of the capability of the CC cells to produce small amounts of steroids (estrogens and mainly progesterone). These hormones, alone or together with other substances (proteins, nutrients, growth factors?), might--around the fertilization time--act positively upon the early embryo itself, as well as on the microenvironment in which the embryo develops, both in vivo and in vitro conditions.

Cell Membrane↗
PubMed1991

Arterial repair after microvascular anastomosis. Scanning and transmission electron microscopy study.

In order to study the morphological aspects of endothelial regeneration and vascular wall reaction after microvascular anastomosis, rat femoral arteries were sectioned and successively sutured (end-to-end anastomosis) with microsurgical techniques. Control arteries and anastomosed vessels (recovered after 1, 4, 7, 14, 21, 30, 60, 120, 180 and 360 days) were studied by means of scanning (SEM) and transmission electron microscopy (TEM). The reendothelialization phenomena started after 7 days and were mainly evident at 21 days. Areas of subendothelial connective tissue with fibrin deposition remained exposed to the blood stream up to 21-30 days. Thrombus formations or post-anastomotic stenosis have been occasionally observed. Regenerating endothelium showed evident morphological differences from the control. These changes mainly consisted of shortened cell length, absence of pinocytotic vesicles, presence of cytoplasmic prolongations, and microvillous proliferations. The arterial wall showed subintimal thickening. The anastomotic site appeared completely covered by new endothelium after 30-60 days. Subintimal vascular wall changes (thickening of the media) as well as slight alterations of endothelial cells (shortened length, reduced number of pinocytotic vesicles) were evident in 60-day vessels. Lumen reduction, due to the protruding of endothelial-covered sutures, was occasionally observed in 60- to 120-day arteries. Endothelial cell morphology normalized after 60-120 days. However, thickening of the media and occasional lumen reduction were observed also after 180-360 days. Although the endothelial regeneration phenomena were clearly evident after 2 weeks, nevertheless the reestablishment of arterial wall took longer time.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1990

Effects of dihydrotestosterone treatment on adrenal gland function and morphology in adult female guinea-pigs.

The effect of chronic treatment of female guinea-pigs with dihydrotestosterone (DHT) on growth and function of the adrenal gland and, in particular, on the reticular zone is described. Two groups of 6 young adult, female guinea-pigs were treated with DHT (1 mg/kg dissolved in peanut oil and injected s.c.) for 30 and 60 days. Two other groups of animals, treated only with oil, were used as controls. At the end of treatment, animals were killed and adrenal glands were quickly removed. Plasma levels of pregnenolone, dehydroepiandrosterone (DHA) and its sulfate (DHA-S), 17 alpha-hydroxyprogesterone, androstenedione, testosterone, estradiol, 11-deoxycortisol, androstenedione, DHT and 3 alpha-androstanediol were determined by R.I.A. following celite microcolumn chromatography. Animals treated for 30 days showed only elevated DHT and 3 alpha-androstanediol plasma levels, whereas animals treated for 60 days also showed increased values of pregnenolone (251 +/- 62 vs 193 +/- 51 ng/dl; P less than 0.05), DHA-S (12,046 +/- 4110 vs 2780 +/- 888 ng/dl; P less than 0.001) and slightly increased values of DHA (110 +/- 31 vs 86.5 +/- 55.4). In the 30-day-treated animals no histological changes were observed, but in the 60-day-treated group the total size as well as cell volumes of the zona reticularis were significantly increased. Normal estrous cycles were observed in the 30-day-treated animals whereas the 60-day-treated animals showed a progressive acyclicity during the second month of treatment. These results indicate that in guinea-pigs, prolonged treatment with DHT induces a growth of the zona reticularis of the adrenal gland associated with increased levels of 5-ene steroids, particularly DHA-S. The mechanisms inducing these modifications are probably mediated by a DHT effect at the hypothalamic-pituitary level. A direct effect of DHT on the zona reticularis, however, cannot be excluded.

Adrenal Glands↗
PubMed1989

The three-dimensional structure of the zona pellucida in growing and atretic ovarian follicles of the mouse. Scanning and transmission electron-microscopic observations using ruthenium red and detergents.

The present study provides further details on the fine-structural three-dimensional architecture of the zona pellucida (ZP) in growing and atretic follicles of mice by use of ruthenium red in combination with the detergents Triton X100 and saponin. These detergents were used for extraction of the "soluble" fraction of the zonal proteins in an attempt to expose the "structural" zonal glycoproteins, which in turn can be viewed as minute three-dimensional networks upon transmission- and scanning electron-microscopic examination. By use of these methods, the ZP of growing follicles appeared to be formed by interconnected filaments which also bind to globular structures building up a three-dimensional lattice. In contrast, the ZP of stage I as well as other (II and III) stages of atretic follicles showed a structure characterized by the presence of closely packed granules connected with short filaments to form a close-mesh reticulum. This structural change of the ZP, which in the present study is also associated with the disappearance of "gap junctions" within the granulosa and cumulus cell population, might represent one of the early events involved in the onset of atresia. These changes, most probably depending on an altered secretory activity of both oocytes and follicle cells, might lead to a degradation of the ZP network structure and to its subsequent increased density (condensation). All these morphodynamic events eventually contribute to a sequestration of the oocyte in the early stage of atresia.

Actin Cytoskeleton↗
PubMed1989

Ultrastructural changes of coronary artery endothelium induced by cardioplegic solutions.

Coronary artery endothelial and myocardial ultrastructure was studied in guinea-pig heart-lung preparations (HLP) subjected to ischemic cardiac arrest induced by three hypothermic solutions. Two of the solutions used had high potassium chloride concentration ("Alabama" and "St. Thomas") while the third, instead, was a bicarbonate buffer (Kreb's solution). Five experimental groups were studied. In group 1 (control) the HLP were not subjected to cardiac arrest. Groups 2, 3, and 4 were subjected to a period of cardiac arrest of 30, 60, and 120 minutes respectively. In group 5, HLP were reperfused with blood for 30 minutes after 60 minutes of cardiac arrest. A thin ring of the left anterior descending coronary artery and myocardial fragments were obtained at the end of each experiment and were analyzed by means of transmission electron microscopy (TEM). Functional parameters were recorded in group 5. HLP perfused with Alabama solution showed a well-preserved endothelium and myocardium. HLP perfused with Krebs solution showed slight changes of the endothelial glycocalix only in group 4. Further, HLP perfused with Krebs solution showed extensive myocardial lesions (groups 3 and 4). These ischemic changes were not completely reversed after reperfusion (group 5). HLP perfused with St. Thomas solution showed only endothelial changes. These lesions were mainly characterized by: disappearance of the glycocalix and pynocytotic vesicles, endothelial cell bulging (group 2), and loss of the endothelial continuity (groups 3, 4, and 5). Hemodynamic parameters were significantly changed only in the Krebs-perfused HLP which showed a deterioration of the cardiac function related to the ischemic damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Is the sperm-binding capability of the zona pellucida linked to its surface structure? A scanning electron microscopic study of human in vitro fertilization.

The structure of the zona pellucida and the early interactions between human oocytes and spermatozoa were investigated in an in vitro fertilization program. Thirty-five mature (preovulatory) oocytes, 10 immature oocytes lacking a germinal vesicle, and 11 atretic oocytes which had not undergone fertilization at 10-20 hr after insemination were studied by light and scanning electron microscopy. Observed through employment of these techniques, the zona pellucida showed two basically different patterns: a mesh-like, spongy structure having wide and/or close meshes; and a compact, smooth surface. The smooth-surfaced zona was most commonly seen in the cultured oocytes belonging to the immature and atretic groups. These observations seem to show that the spongy appearance of the zona pellucida is related mainly to oocyte development and maturity. In this study, greater numbers of penetrating spermatozoa were noted on oocytes showing the mesh-like zona, in contrast to the presence of a few sperm flattened against its surface or the frank absence of sperm associated with oocytes having the more compact, smooth zona. It is likely that the condensation of the outer aspect of the zona pellucida causes a disorientation of sperm-binding sites, which would probably result in markedly reduced binding and penetration capacity with spermatozoa. These changes might ultimately lead to impairment of in vitro oocyte fertilizability.

Fertilization in Vitro↗
PubMed1988

Antisperm antibodies detection with the immunobead test as viewed by TEM.

The immunobead test (IBT) was used for the detection of antisperm antibodies. Scanning electron microscopy (SEM) was used to study ultrastructural aspects of this technique. This brief communication aims to present some ultrastructural evidence using transmission electron microscopy (TEM).

Antibodies↗
PubMed1987

[Involvement of the polypeptide system and ACE in Crohn disease].

The polypeptidyc system was studied and serum concentrations of ACE (Angiotension Converting Enzyme) were assayed in patients with Crohn's disease in the active and stabilising phases. The study was undertaken on the assumption that as a granulomatous condition Crohn's disease involves the polypeptidyc system in much the same way as in sarcoidosis. The results confirm the hypothesis revealing a significant increase in ACE levels in patients with the active disease, whereas levels in the stabilized disease were lower than in the controls. It is suggested that, as in sarcoidosis, ACE levels are useful in the diagnosis, prognosis and follow-up of Crohn's disease, especially in relation to the use of steroid drugs.

Adult↗