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Biomedical subjects

E Bertelli

Publications and source records attributed to E Bertelli.

At least 19 recordsLinked to original sources
PubMed2005

Nestin expression in normal adrenal gland and adrenocortical tumors.

Human adrenocortical cells have been shown to express cytokeratins and vimentin. Nestin is an intermediate filament protein that is mainly expressed in the developing nervous system and that has been recently reported in rat adrenal gland as well. Using immunohistochemical and biochemical approaches, the present study demonstrates that nestin is constantly expressed in situ in the cortex of normal human adrenal glands. Nestin expressing cells were prevalently located in the zona reticularis but some positive cells could be spotted in the zona fasciculata as well. Moreover, patches of nestin-positive cells have been constantly detected on sections of cortical adenomas. In contrast, adrenal carcinomas displayed a variable number of nestin-immunoreactive cells that in some cases were virtually absent. Samples of renal clear cell carcinoma metastasis in the adrenals were also examined which did not show nestin-immunoreactivity. We propose that a positive nestin-immunoreaction could be useful in differential diagnosis of clear cell tumors in adrenal glands.

Adenocarcinoma, Clear Cell↗
PubMed2003

Angiotensinogen localization and secretion in the rat pancreas.

Renin and angiotensinogen have been previously found in the rat pancreas, and angiotensin receptors have been located in the apical domain of duct cells. To evaluate the possibility that angiotensin II could be generated within the duct system, we decided to determine whether angiotensinogen is present in rat pancreatic juice and the angiotensinogen-immunoreactive pancreatic cell types that could be responsible for its production. Angiotensinogen was detected in significant amounts by Western blotting in pancreatic juice collected from several individual rats. Different isoforms between plasma and pancreatic juice angiotensinogens were demonstrated by isoelectric focusing. Immunocytochemical experiments revealed angiotensinogen-immunoreactive cells at the periphery of the islets of Langerhans, and confocal microscopy demonstrated that most angiotensinogen-immunoreactive cells were glucagon-secreting cells. Secretion of angiotensinogen did not follow the regulated secretory pathway since it was absent from the glucagon-containing granules. This was confirmed by electron microscopy immunocytochemistry. Duct and acinar cells did not express angiotensinogen at an immunocytochemical detectable level. The present findings indicated an exocrine secretion of angiotensinogen by glucagon-secreting cells and suggest that one of the final targets of the local pancreatic renin-angiotensin system may be the duct epithelium.

Angiotensinogen↗
PubMed2001

Pancreatic lymphatic system in rodents.

The lymphatic network of the pancreas has been little investigated and recent studies have provided contrasting data. This research is aimed to supply the morphologic basis to outline the involvement of the lymphatic system in pancreatic pathology. Guinea pigs, rats, and mice were anesthetized with ether and sacrificed with the same anesthetic. Pieces of pancreas were processed for transmission electron microscopy. Semithin sections were observed by light microscopy and, after positive identification by transmission electron microscopy, lymphatics were followed with long series of consecutive sections to define their distribution. Lymphatics were detected in the pancreas of all the animals both in the inter and the intralobular sites. Closer relations with the exocrine parenchyma (ducts and acini) were observed in guinea pig pancreas. Remarkably, interesting relationships between lymphatics and endocrine tissue were observed in all the animals. Overall, however, the lymphatic network of rat pancreas was less develop and preferentially associated with blood vessels. The distribution of the pancreatic lymphatic network appears consistent with an active role in pancreatic pathology.

Animals↗
PubMed2001

Association between islets of Langerhans and pancreatic ductal system in adult rat. Where endocrine and exocrine meet together?

AIMS/HYPOTHESIS: Studies on the functional and morphological relations between exocrine and endocrine pancreas have been conducted mainly to disclose the influence of islets of Langerhans on acinar parenchyma. Less attention has been paid to the relations occurring between islets and pancreatic ducts. METHODS: A series of consecutive sections of normal adult rat pancreas were double stained with islet (hormones) and duct (cytokeratin 20) markers. Electron microscopy was conducted to investigate the ultra-structural features of duct-islet relations and anti-insulin immunogold labelling was carried out to reveal the presence of insulin in the pancreatic duct system. RESULTS: Consecutive double-stained sections demonstrated that 73.60 +/- 2.97% of the islets were attached to the ducts. For each series, 93.48 +/- 5.43 % of the islets contacting the duct tree were associated with small-sized ducts or centroacinar cells. Electron microscopy revealed that some insulin and somatostatin cells do face the duct lumen. Insulin was detected within the duct lumen and in the endosomal compartment of the duct cells. CONCLUSIONS/INTERPRETATION: The finding that most islets are connected with the duct system in the adult pancreas is discussed in terms of hormone secretion into the ducts, islet histogenesis and the relation among the three tissue components of the pancreas, the endocrine, the exocrine and the duct system.

Animals↗
PubMed2000

Glial fibrillary acidic protein (GFAP)-like immunoreactivity in rat endocrine pancreas.

The study of intermediate filament expression in the pancreatic epithelium has been previously focused almost exclusively on cytokeratins. Transient vimentin immunoreactivity has also been detected in duct cells of rat fetal pancreas. Here we report that, in rat pancreas, intense GFAP-like immunoreactivity is detectable in a subpopulation of endocrine cells located in the periphery of the islet of Langerhans. In addition, staining appeared to be preferentially localized to the apical pole of the cells. Two different polyclonal antibodies were employed in this study, with analogous results. Staining of consecutive sections with anti-GFAP, anti-glucagon, and anti-somatostatin antibodies demonstrates that GFAP-like immunoreactivity is present in glucagon-secreting cells. The relevance of this finding is discussed. (J Histochem Cytochem 48:259-265, 2000)

Animals↗
PubMed2000

GFAP is expressed as a major soluble pool associated with glucagon secretory granules in A-cells of mouse pancreas.

To elucidate the role of intermediate filament proteins in endocrine cells, we investigated the expression and subcellular distribution of GFAP in mouse islets of Langerhans. For this purpose, combined immunocytochemical and biochemical analysis with a panel of antibodies was carried out to identify GFAP-immunoreactive cells in mouse endocrine pancreas. Cell fractionation into NP-40-soluble and detergent/high salt-insoluble components was performed to assess whether GFAP was located in the cytosolic and/or cytoskeletal compartments of immunoreactive cells. Immunoelectron microscopic analysis was carried out to determine the subcellular distribution of the protein. Peripheral islet cells were stained with anti-GFAP antiserum. These cells were identified as glucagon-secreting cells by immunocytochemical staining of consecutive sections with anti-somatostatin, anti-GFAP, and anti-glucagon antisera. Western blotting analysis of both NP-40-soluble and detergent/high-salt insoluble fractions of isolated islets of Langerhans allowed detection of GFAP in both cytosolic and cytoskeletal compartments. Interestingly, however, the former location was highly predominant. In addition, immunoelectron microscopy localized GFAP associated with the periphery of secretory granules. On the basis of these results, an intriguing role for GFAP in secretory events should be strongly suspected.(J Histochem Cytochem 48:1233-1242, 2000)

Animals↗
PubMed1999

Dye leakage and SEM study of roots obturated with Thermafill and dentin bonding agent.

The apical seal of roots obturated with a dentin bonding agent and Thermafill with and without the use of sodium hypochlorite as an irrigating solution was compared by a dye leakage test. Roots obturated with Thermafill and a zinc oxide eugenol sealer were used as controls. Thirty-eight roots were prepared chemomechanically and divided into three experimental groups. The teeth of group 1 were filled with Thermafill and the dentin bonding agent using sodium hypochlorite as the irrigant. The teeth of group 2 were filled in the same way, but saline solution was used as the irrigant. Before the root canal was filled the smear layer was removed from the root canal walls of both groups by rinsing the root canal with a 17% EDTA solution. The teeth of group 3 were filled with Thermafill and a zinc oxide eugenol sealer. The teeth were immersed in 2% methylene blue solution. The root fillings of groups 1 and 2 leaked significantly more than those of group 3. The resin-dentin-guttapercha interface of group 1 was observed by scanning electron microscopy and showed a typical hybrid layer. An intimate contact between resin and dentin was present in group 2, but a resin-dentin interdiffusion zone was only occasionally observed. The use of dental adhesives and the hybrid layer formation did not improve the seal of Thermafill root canal fillings.

Coloring Agents↗
PubMed1998

The arterial blood supply of the pancreas: a review. V. The dorsal pancreatic artery. An anatomic review and a radiologic study.

The present article is the fifth part of a comprehensive review on the arterial blood supply of the pancreas and deals with the dorsal pancreatic artery. The aim of this review is to summarise the anatomic studies, starting from Haller's reports, and to supply, as far as possible with original material, angiographic evidence for the classic anatomic notions. For this purpose, the overall research was carried out by studying 1015 selective angiographies (celiac trunk and its branches, superior mesenteric artery) taken from the angiographic archives of the Institutes of Radiology of Siena, Rome (Catholic University), and Perugia. Angiographically, the authors could demonstrate the dorsal pancreatic artery, present in most instances, as arising from the splenic artery, common hepatic artery, superior mesenteric artery or celiac trunk and accessory right hepatic artery as coming from the superior mesenteric artery. Variations in the course and length of the dorsal pancreatic artery were demonstrated as well as some collateral branches. The authors underline the discordant opinions still existing regarding the incidence of the different ways the dorsal pancreatic artery arises, and discuss its uncertain embryologic development and surgical relevance.

Angiography↗
PubMed1997

Intermediate endocrine-acinar pancreatic cells in duct ligation conditions.

When tissues were subjected to 24 h of duct ligation, intermediate pancreatic cells simultaneously displaying endocrine and exocrine phenotypes appeared. Immunocytochemistry by laser scanning confocal microscopy revealed the appearance of a large number of these cells coexpressing insulin and amylase. These cells were located within the islets of Langerhans as well as in the acinar parenchyma. They were also detected in a culture system of isolated pancreatic cells. With the use of immunoelectron microscopy, two types of secretory granules were identified in these cells. One was insulin immunoreactive, whereas the other, resembling zymogen granules, contained amylase. Occasionally, some small granules displayed a double labeling for both secretory proteins. Numerous crinophagic bodies and autophagosomes containing insulin and/or amylase were also present. In situ hybridization, applied with the specific probes, confirmed the presence of both insulin and amylase mRNAs in these cells. Because duct ligation is known to induce insulin cell proliferation, the present results confirm that endocrine-acinar cells do appear in such condition and may represent intermediate steps in a transdifferentiating process.

Amylases↗
PubMed1997

The arterial blood supply of the pancreas: a review. IV. The anterior inferior and posterior pancreaticoduodenal aa., and minor sources of blood supply for the head of the pancreas. An anatomical review and radiologic study.

The present article is the fourth part of a comprehensive review of the arterial blood supply of the pancreas and completes the study of the arterial vascularization of the pancreatic head dealing with the anterior inferior and posterior inferior pancreaticoduodenal aa. and with some minor sources of blood supply not involving the classical system of the pancreaticoduodenal arches. The aim of this review is to summarise the anatomical studies, starting from Haller's reports, and to supply, as far as possible with original material, angiographic evidence for the classic anatomical concepts. For this purpose, 1015 selective angiographs (celiac trunk and its branches, superior mesenteric a.) were taken from the angiographic archives of the Institutes of Radiology of Siena, Rome (Catholic University), and Perugia. These demonstrated the anterior inferior pancreaticoduodenal a., present in most instances, as arising from the inferior pancreaticoduodenal a., from a common trunk with the posterior inferior pancreaticoduodenal a. and the 1st jejunal a., from the 1st jejunal a. or from the superior mesenteric a.; on the other hand, the posterior inferior pancreaticoduodenal a. was more variable, originating from the inferior pancreaticoduodenal a., from a common trunk with the anterior inferior pancreaticoduodenal a. and the 1st jejunal a., from the superior mesenteric a., from the dorsal pancreatic a., or from a right accessory hepatic a. coming from the superior mesenteric a. In addition, minor branches to the head of the pancreas arose from the gastroduodenal a., the dorsal pancreatic a., the common hepatic a. and the inferior right phrenic a. Other origins of the inferior pancreaticoduodenal aa. previously reported, but not angiographically detectable with certainty, as well as further minor sources of blood supply to the head of the pancreas, have been listed. The differing opinions regarding the incidence of the various ways the inferior pancreaticoduodenal aa. arise are discussed and an attempt is made to explain the variability of the vascular anatomy of the pancreatic head on embryologic grounds.

Arteries↗
PubMed1996

Modifications of the follicle-associated epithelium by short-term exposure to a non-intestinal bacterium.

This study was undertaken in order to study the effects of short-term exposure of the follicle-associated epithelium (FAE) of rabbit Peyer's patches to a non-intestinal, Gram-positive bacterium. Isolated ileal loops, each containing one Peyer's patch (PP), were stimulated for short periods of time (30 and 60 min) with Streptococcus pneumoniae R36a, a micro-organism normally not present in the intestinal area. Samples from antigen-stimulated and control Peyer's patches were analysed by light (LM), transmission electron (TEM), and scanning electron microscopy (SEM). Stimulation with living pneumococci induced dramatic changes in FAE architecture and morphology. A massive passage of cells from lymphoid tissue to the FAE was rapidly detectable, accompanied by alterations of the FAE surface, with a marked increase of M-cell area. Furthermore, TEM analysis revealed that M cells were able to internalize living pneumococci. S. pneumoniae R36a is a valid experimental model for the further study of the unique antigen sampling function which characterizes the highly specialized FAE in Peyer's patches.

Animals↗
PubMed1996

The arterial blood supply of the pancreas: a review. III. The inferior pancreaticoduodenal artery. An anatomical review and a radiological study.

This article is the third part of a comprehensive review on the pancreatic arterial blood supply and deals with the inferior pancreaticoduodenal a. The aim of this review is to summarise the anatomical studies, starting from Haller's reports, and to supply as far as possible, with original material, angiographic evidences for the classic anatomical notions. For this purpose, the overall research was carried out by picking out and studying 1015 selective angiographies (celiac trunk and its branches, superior mesenteric a.) taken from the angiographic archives of the Institutes of Radiology of Siena, Rome (Catholic University), and Perugia. Angiographically, the authors observed the inferior pancreaticoduodenal a., present in most instances, as arising from the superior mesenteric a., from the right accessory hepatic a., or from a common trunk with the first or the first two jejunal aa. Some variations of the course have been shown. The authors underline and discuss the discordant opinions still existing regarding the incidence of the different ways the inferior pancreaticoduodenal a. arises and the surgical importance of the variation of origin of this artery.

Angiography↗
PubMed1996

The arterial blood supply of the pancreas: a review. II. The posterior superior pancreaticoduodenal artery. An anatomical and radiological study.

The present paper is the second part of a comprehensive review of the arterial blood supply of the pancreas and deals with the posterior superior pancreaticoduodenal artery. The aim of this review is to summarise the anatomical studies, starting from Haller's reports, and to supply as far as possible, with original material, angiographic evidences for the classic anatomical notions. For this purpose, the overall research was carried out by picking out and studying 1015 selective angiographies (celiac trunk and its branches, superior mesenteric a.) taken from the angiographic archives of the Institutes of Radiology of Siena, Rome (University of Sacro Cuore, Catholic University), and Perugia. Angiographically, many possible different sources of the posterior superior pancreaticoduodenal a. (superior pancreaticoduodenal a., proper hepatic a., right hepatic a., left hepatic a., superior mesenteric a., accessory and replaced right hepatic a. coming from the superior mesenteric a.) have been demonstrated, as have rare variations of the course and a small number of collateral branches (retroduodenal a. and ventral commissural a.). Moreover, the authors underline the discordant opinions still existing regarding the incidence of the different ways the posterior superior pancreaticoduodenal a. arises.

Celiac Artery↗
PubMed1995

Three-dimensional (3D-) reconstruction of M cells in rabbit Peyer's patches: definition of the intraepithelial compartment of the follicle-associated epithelium.

One of the major cell components of the rabbit follicle-associated epithelium is represented by the M cells. M cells are able to harbour variable amounts of immunocompetent cells inside peculiar invaginations of their basolateral cytoplasmic membrane, currently referred to as "pockets." This study provides a description of the exact spatial relationships between the M cells and the cells harboured in these so-called "pockets." Pieces of Peyer's patches, taken from the small intestine of an adult male rabbit, were treated as usual for conventional electron microscopy. Consecutive semithin and ultrathin sections were made through the entire thickness of the follicle-associated epithelium along planes parallel to the mucosal surface. Micrographs, taken from the ultrathin sections, were transposed into a software MacDraw Pro to obtain a computerized three-dimensional reconstruction. Three-dimensional reconstruction of the M cells showed that the "pockets" were not formed by mere invaginations of the cytoplasmic membrane, but that they resulted from the branching of the supranuclear portion of the M cell cytoplasm around the M cell-infiltrating lymphocytes. These intrusive cells could be found inside the "pockets" or lined up with one another, in vertical columns, bordering on the basal aspect of the M cells. The particular arrangement of the M cell apical cytoplasm created a labyrinth within the follicle-associated epithelium, which could be assumed as a real intraepithelial compartment expandable virtually throughout all the epithelium. The functional meaning of the intraepithelial compartment delimited by the M cells and its possible role is discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

The arterial blood supply of the pancreas: a review. I. The superior pancreaticoduodenal and the anterior superior pancreaticoduodenal arteries. An anatomical and radiological study.

The gross anatomy of the pancreatic blood supply has been subjected to numerous studies. The results of such studies, however, have never been summarized in detail, even in the most important textbooks. For this reason, a certain confusion was generated, especially regarding the interpretation of the nomenclature used to identify pancreatic arteries. This review summarizes more than two centuries of studies of the gross anatomy of the pancreatic blood supply, clarifies the arterial nomenclature, and underlines the aspects about which anatomists are not in agreement. Moreover, it supplies, as far as possible, documentary evidence for numerous observations previously reported only verbally. For this purpose, more than 200 references were directly consulted to provide the anatomical background of the topic, and more than 1000 angiograms were studied to support the review with original figures. The present paper, on the superior pancreaticoduodenal and anterior superior pancreaticoduodenal arteries, is the first of a series of articles dealing with the pancreatic blood supply.

Aorta, Abdominal↗
PubMed1995

Uptake of a gram-positive bacterium (Streptococcus pneumoniae R36a) by the M cells of rabbit Peyer's patches.

The epithelium associated with the lymphoid follicles of Peyer's patches differs from the villi epithelium by the presence of M cells. The main function of these cells is to take up antigens (inert material, viruses and bacteria) from the intestinal lumen. The M cells are able to internalize various different gram-negative bacteria. In order to show the M cells ability to interact and take up a gram-positive bacterium, we exposed rabbit Peyer's patches to Streptococcus pneumoniae R36a. Using the isolated ileal loop technique, Peyer's patches were incubated with a bacterial suspension for varying periods (15, 30, 60, 100 minutes). The bacteria were found outside and inside the M cells. The internalized streptococci could be found in the M cell cytoplasm, in the cytoplasmic "pockets" and inside the intraepithelial lymphoid cells. The finding of internalized bacteria with their damaged walls suggests the possibility that M cells are able to modify internalized antigens in the same way as the antigen presenting cells.

Animals↗
PubMed1995

Arrangement of the small intestine lymphatic network in the Peyer's patches of the mouse. A light and transmission electron microscopic study.

The lymphatic network in Peyer's patches has been previously studied by scanning electron microscopy in rabbit and sheep. So far, data on the Peyer's patch lymphatic network obtained by light and transmission electron microscopy are still lacking. The present work was carried out on several series of consecutive thick and semithin sections of mouse Peyer's patches. Ultrastructural analyses were performed on ultrathin sections by traditional transmission electron microscopy. Lymph vessels were detected in the parafollicular and subfollicular areas of Peyer's patches. Two independent lymphatic plexuses, the muscularis mucosae lymphatic plexus and the subfollicular plexus, were identified respectively in the mucosal and submucosal layers. These lymphatic plexuses joined outside the patch, both draining into the submucosal lymphatic network of the small intestine. At the ultrastructural level, the muscularis mucosae lymphatic plexus, and the lymph vessels draining into it, showed a close association with bundles of smooth muscle cells. Numerous nerve fibres were detected in proximity to the lymphatic endothelium and, in some cases, synapse-like neuroendothelial associations were observed. We report here the lymph vessel organization observed in mouse Peyer's patches and discuss the meaning of the presence of subendothelial nerve terminals.

Animals↗