Biomedical subjects

M Morroni

Publications and source records attributed to M Morroni.

At least 19 recordsLinked to original sources

PubMed2000

Primary alveolar soft part sarcoma of the stomach: a case report and review.

Alveolar soft part sarcoma (ASPS) is a rare tumor typically located in skeletal muscles and muscolofascial planes. Isolated cases of ASPS have been described as arising in the viscera. We report a mesenchymal tumor of the stomach in a 54-year-old Italian woman without evidence of primary neoplasm elsewhere ten years following the initial diagnosis. The histologic, histochemical, immunohistochemical, and electron microscopic findings were all consistent with the diagnosis of ASPS and allowed differentiating it from morphologically similar and more common tumors, such as metastatic renal cell carcinoma and paraganglioma. The patient is alive and well ten years following the initial presentation.

Biomarkers, Tumor↗

PubMed1998

Sensory nerves affect the recruitment and differentiation of rat periovarian brown adipocytes during cold acclimation.

Rat periovarian adipose tissue contains a low number of uncoupling protein-expressing brown adipocytes scattered into lobules of white fat. Their increase following cold acclimation is matched by a major increase in noradrenergic and neuropeptide Y-, substance P- and calcitonin gene-related peptide-containing nerves. To ascertain whether periovarian fat is provided with sensory nerves, and whether any relationship exists between such nerves (in particular the calcitonin gene-related peptide-containing fibers found in cold-acclimated rats in close association with brown adipocytes) and brown fat recruitment, the effects of capsaicin desensitization on neuropeptide-containing nerves and brown adipocyte density were studied in the periovarian tissue of rats kept at 20 degrees C and on a group acclimated to 4 degrees C for 14 days. In both groups, systemic capsaicin administration considerably reduced the expression of substance P and calcitonin gene-related peptide in vascular-nerve bundles and parenchyma. In cold-acclimated rats, the increase in brown adipocyte density was significantly checked by capsaicin administration (21.11 versus 7.96 brown adipocytes/mm2, P<0.05). Finally, ultrastructural investigation showed the occurrence of brown adipocyte precursors filled with aggregates of glycogen and poorly differentiated multilocular adipocytes in capsaicin-treated cold-acclimated rats. These data suggest that periovarian adipose tissue is indeed provided with sensory neuropeptide-containing nerves and that they play a role in the recruitment and differentiation of brown adipocytes.

Acclimatization↗

PubMed1998

Hypomelanosis of Ito: a case report with clinical and ultrastructural data.

Hypomelanosis of Ito (HI) is an uncommon skin disorder characterized by the presence of hypochromic areas associated with visceral abnormalities, the most common being neurological, muscular, skeletal and ocular. The authors describe a typical case of hypomelanosis of Ito in a 7-year-old child. The patient was obese, suffered from scoliosis, flat feet and had a bilateral genu valgus. No neurological, ophthalmological or dental malformations were noted. An electron microscopic study of a hypomelanotic area showed decreased functional activity in the melanocytes, which contained only a few rudimentary cytoplasmatic projections and poorly developed organelles. In addition, there was a reduction in the number of mature melanosomes.

Child↗

PubMed1996

Tyrosine hydroxylase, neuropeptide Y, substance P, calcitonin gene-related peptide and vasoactive intestinal peptide in nerves of rat periovarian adipose tissue: an immunohistochemical and ultrastructural investigation.

Rat periovarian adipose tissue contains unilocular adipocytes and some multilocular adipocytes that, following acclimation to cold, become more numerous and give rise to periovarian brown fat areas. We studied the occurrence and distribution of tyrosine hydroxylase, neuropeptide Y, substance P, calcitonin gene-related peptide, vasoactive intestinal peptide, methionine enkephalin, neurotensin, galanin, and cholecystokinin 9-20 in the nerves of rat periovarian tissue maintained at 20 degrees C (control rats), acclimated at 4 degrees C (cold acclimated rats) and at 28 degrees C (warm-acclimated rats). In the periovarian tissue of control and warm-acclimated rats, tyrosine hydroxylase-like, neuropeptide Y-like, substance P-like and calcitonin gene-related peptide-like immunoreactive elements (putative nerves) were present in the blood vessels. In the periovarian tissue of cold-acclimated rats, we found: (1) a more widespread vascular distribution of these neuropeptides; (2) tyrosine hydroxylase-like and calcitonin gene-related peptide-like immunoreactive elements among paucilocular and multilocular adipocytes (parenchymal-like nerves); (3) vasoactive intestinal peptide-like immunoreactive elements in some arteries. Investigation by EM showed the presence of heterogeneous non-myelinated axons both associated with capillaries and among paucilocular and multilocular adipocytes (parenchymal fibres) in periovarian brown fat areas. In conclusion, periovarian brown fat contains the same neuropeptides, with the same vascular and parenchymal distribution, already seen in typical depots of brown fat.

Adipose Tissue, Brown↗

PubMed1996

Codistribution of basic fibroblast growth factor and heparan sulfate proteoglycan in the growth zones of the human placenta.

In order to obtain an insight into morphogenetic processes such as angiogenesis, cell proliferation, and tissue remodeling we have studied the localization of basic fibroblast growth factor (bFGF) and heparan sulfate proteoglycan (HSPG) in the human placenta by immunohistochemistry. Positive reaction product for bFGF is found mainly in the villous trophoblastic covering and for HSPG in the villous basement membranes. A codistribution of the two molecules is detectable in first trimester placental tissue, in areas previously identified as being responsible for the growth of the villous tree, i.e., in the mesenchymal villi and the cytotrophoblastic cell islands and cell columns, both consisting of extravillous trophoblast. HSPG and bFGF are codistributed in the distal half of the villous stroma in the mesenchymal villi. In cell islands and cell columns, bFGF is detectable in the cytoplasm of the extravillous cytotrophoblastic cells, whereas HSPG is localized between the extravillous cytotrophoblastic cells and in their cytoplasm. HSPG-bFGF codistribution in term placenta is confined to the walls of fetal vessels and to some extravillous cytotrophoblastic cells in the basal plate. The codistribution of bFGF and HSPG in first trimester placental tissue suggests that these two molecules play a pivotal role in the morphogenetic processes mentioned above in early stages of gestation.

Chorionic Villi↗

PubMed1995

Brown adipocyte precursor cells: a morphological study.

The origin of brown adipocyte precursor cells is to date unknown. Some authors believe they arise from vascular cells, others from interstitial cells. The purpose of the present ultrastructural study was to find markers in rat fetal and perinatal adipose tissue that can be used to identify brown adipose precursor cells. The study was carried out on the interscapular brown adipose tissue of fetal (fetuses of 19 and 21 days) and perinatal rats (pups of 4 and 12 hours and of 1, 3, 5, 7, 9, 11, 13, and 15 days). The analysis focused on stem cells and showed the characteristic presence of typical mitochondria which make their identification as brown adipocyte precursor cells inequivocal. These cells were frequently observed in a pericytic position. Also some endothelial cells were characterised by typical mitochondria and abundant glycogen. These data seem to support the hypothesis that brown adipocytes originate from vascular cells.

Adipocytes↗

PubMed1995

Immunohistochemical, ultrastructural and morphometric evidence for brown adipose tissue recruitment due to cold acclimation in old rats.

OBJECTIVE: The aim of this work was to study the reactivity to chronic cold stress of interscapular brown adipose tissue (IBAT) in old rats by stereological, immunohistochemical and ultrastructural methods. DESIGN: Five 2-year-old rats were cold-acclimated at 4 degrees C for 4 weeks and six rats were used as controls (20-23 degrees C). MEASUREMENTS: The following were measured: IBAT volume and weight; unilocular and multilocular brown adipocyte content; preadipocyte number; multilocular cell mitochondrial area; cristae length and density per mitochondrion, and immunoreactivity for the brown adipose tissue specific uncoupling protein (UCP). RESULTS: Following cold acclimation, IBAT increased significantly in weight, volume, relative mass and number of multilocular adipocytes (170%). The number of unilocular adipocytes did not vary significantly. Multilocular adipocytes of both cold-acclimated rats and controls expressed the uncoupling protein, but in the experimental group cristae length and density per mitochondrion were significantly higher. Multilocular adipocyte precursors were observed in only one cold-acclimated rat but not in controls. CONCLUSION: The response of brown adipose tissue of old rats to chronic cold stimulus is similar to that observed in young and adult rats. Cold acclimation induces brown adipocyte recruitment: their number increases significantly, they test UCP-positive and their mitochondria are significantly more active than in controls. On the other hand, the number of unilocular adipocytes is not significantly affected, which may serve to improve the utilization of the heat produced by thermogenesis.

Acclimatization↗

PubMed1995

Subcutaneous nodules in a patient hyposensitized with aluminium-containing allergen extracts: a microanalytical study.

Electron spectroscopic imaging (ESI) is a recent tool for electron microscopic analysis which permits the recognition of the distribution of elements in a specimen, with a spatial resolution up to 5 nm. The authors performed the ESI together with X-ray microanalysis (EDX) and transmission electron microscopy to study granulomatous subcutaneous nodules in a patient who had undergone a desensitising therapy with an aluminium-containing vaccine. Aluminium was detected both by EDX and ESI, mainly in lysosomes of histiocytes containing needle-shaped material in a lucent matrix. However, ESI provided a better localization of aluminium with respect to EDX. This result suggests that the identification of aluminium-containing structures cannot be obtained only by ultrastructural morphology and underlines the utility of a microanalitycal study for a correct diagnosis in the presence of a needle-shaped deposition of dense material in lysosomes.

Aluminum↗

PubMed1994

Quantitative evaluations of gap junctions in old rat brown adipose tissue after cold acclimation: a freeze-fracture and ultra-structural study.

The morphological and functional modifications of brown adipose tissue (BAT), the tissue responsible for non-shivering thermogenesis, are well established during the phases of active stimulation (i.e. neonatal period and cold acclimation) in young animals. The 'active' brown adipocytes are filled with numerous small lipid vacuoles and large mitochondria packed with cristae rich in the protonophore uncoupling protein (UCP), whereas the 'quiescent' cell shows larger, confluent vacuoles and smaller mitochondria with rarefied cristae poor of the uncoupling protein. It is well known from literature that also gap junctions (gjs), responsible for the electrical coupling among adjacent adipocytes, modify their size following the physiological stimulus in young animals. This is in agreement with the morphology of the functionally active brown adipocyte, i.e. the multilocular, UCP-positive cell. Although the presence of the BAT in old animals is well documented, less is known about its reactivity to physiological stimuli. The present work demonstrates that after cold acclimation brown adipocytes of old rats (2 years) change their ultrastructure in a similar way as in young rats. A quantitative analysis of gap junction areas on replicas obtained by the freeze fracture technique, showed that gj increase in size (mean area 53.2 vs 110.4 x 10(-3) microns2, p = 0.003). All these morphological modifications are quite similar to those observed in BAT of young and young adult rats, supporting the hypothesis of a physiological role of brown adipose tissue at every age.

Acclimatization↗

PubMed1994

Electron spectroscopic imaging of secretory granules in human eccrine sweat glands.

A study of human eccrine sweat glands by electron spectroscopic imaging has been performed. A high nitrogen content in secretory granules of the dark mucous cells has been found while mucous cells in the digestive or respiratory systems did not contain nitrogen detectable in our experimental conditions. High concentrations of nitrogen were found in zymogenic granules and in the core of the granules in the eosinophilic leucocytes. Our findings seem to suggest that the granules of the dark secretory cells are composed not only of mucoid substances but contain also high concentrations of proteins. The descriptive term "granulated cells" seems to be more correct than "mucous cells" to indicate these elements.

Adult↗

PubMed1993

S-100 protein in rat brown adipose tissue under different functional conditions: a morphological, immunocytochemical, and immunochemical study.

The brown adipose tissue (BAT) is responsible for nonshivering thermogenesis, exhibiting changes in cell morphology related to the functional conditions. In stimulated BAT (neonatal period, cold acclimation) the large majority of adipocytes become multilocular and active, while in inactive BAT (warm acclimation) most cells are pauci- or unilocular and inactive, very similar to white adipocytes. It is well known that white adipocytes are sites of concentration of S-100, a calcium-binding protein originally isolated from the nervous system and later detected also in nonneural cell types, whereas data on the possible presence of this protein in BAT are lacking. The present study used morphological, immunocytochemical, and immunochemical methods to investigate the presence of S-100 protein in BAT under different functional conditions. We found that S-100 was present in both stimulated and inactive BAT and that is was expressed in significantly higher quantities in the latter than in the former. The multilocular cells were always negative (in both active and inactive tissue), whereas the pauci- and unilocular cells were always S-100-positive under both functional conditions. These data suggest that only pauci- and unilocular brown adipocytes express S-100 protein, thus manifesting a possible relationship between S-100 and cell morphology.

Adipose Tissue, Brown↗

PubMed1992

Ultrastructural modifications in one case of hairy cell leukemia during alpha-interferon therapy.

There are many reports concerning the morphology of hairy cell leukemia (HCL), but, to our knowledge, there are no data on the ultrastructural modifications of HCL during interferon therapy. The ultrastructural modifications of neoplastic cells in peripheral blood in a case of HCL were investigated before and 2 and 4 months after beginning treatment with human lymphoblastoid alpha-interferon. Before therapy, hairy cells displayed the typical cytoplasmic projections, and 4% contained ribosome-lamellae complexes (RLC) (the cells contained up to 7 RLC). Two months from the beginning of therapy, hairy cells had shorter projections, RLC had disappeared, and tubuloreticular structures (TRS) had appeared in 2.2% of the elements. Four months from the beginning of therapy, TRS persisted in 2.3% of hairy cells, cylindrical confronting cisternae (CCC) appeared in 6.8% of the cells, and uncommon RLC, in close contact with the rough endoplasmic reticulum and nuclear membrane, were found in 1.5% of the elements. The cells contained up to 3 RLC. Our data confirm that interferon stimulates the synthesis of TRS and CCC, whereas the reappearance of uncommon forms of RLC could reflect their neosynthesis, possibly related to the interferon therapy. The frequent findings of a close contact between RLC and nuclear membrane support the view that RLC are derived not only from rough endoplasmic reticulum, but also from the nuclear membrane.

Adult↗

PubMed1992

Parathyroid glands in primary hyperparathyroidism: an ultrastructural morphometric study of 25 cases.

In parathyroid glands removed from patients with primary hyperparathyroidism (pHPT), hyperplasias and adenomas cannot be distinguished from one another by light microscopy when only one gland is available for examination. When a second gland is available, it is necessary to establish whether it is normal, suppressed, or hyperplastic. This distinction may be difficult, and the main criterion is the amount of cytoplasmic lipid in the parenchymal cells. If the lipid is abundant, the gland is considered normal or suppressed, and if it is scanty, the gland is interpreted as hyperplastic. We have performed a morphometric ultrastructural study to test the reliability of this criterion. Twenty-five adenomatous glands removed from patients with pHPT, when compared with glands of normal size from euparathyroid patients, showed a significant increase in the parameters indicative of metabolic activity, namely the size of the Golgi apparatus, the amount of rough endoplasmic reticulum, and the length of plasmalemmas. In addition, the amount of cytoplasmic lipid was significantly reduced. Furthermore, 25 glands of normal size removed from the same patients with pHPT showed an amount of lipid similar to that of normal glands from euparathyroid patients. However, all the parameters indicative of metabolic activity were significantly higher than those in glands from euparathyroid patients and comparable to those found in adenomatous glands. These results suggest that in pHPT, normal-size glands are as active as adenomatous glands, regardless of a higher lipid content.

Adenoma↗

PubMed1992

Occurrence of brown adipocytes in rat white adipose tissue: molecular and morphological characterization.

Brown adipocytes are thermogenic cells which play an important role in energy balance. Their thermogenic activity is due to the presence of a mitochondrial uncoupling protein (UCP). Until recently, it was admitted that in rodents brown adipocytes were mainly located in classical brown adipose tissue (BAT). In the present study, we have investigated the presence of UCP protein or mRNA in white adipose tissue (WAT) of rats. Using polymerase chain reaction or Northern blot hybridization, UCP mRNA was detected in mesenteric, epidydimal, retroperitoneal, inguinal and particularly in periovarian adipose depots. The uncoupling protein was detected by Western blotting in mitochondria from periovarian adipose tissue. When rats were submitted to cold or to treatment with a beta-adrenoceptor agonist, UCP expression was increased in this tissue as in typical brown fat. Moreover, the expression was decreased in obese fa/fa rats compared to lean controls. Morphological studies showed that periovarian adipose tissue of rats kept at 24 degrees C contained cells with numerous typical BAT mitochondria with or without multilocular lipid droplets. Immunocytochemistry confirmed that multilocular cells expressed mitochondrial UCP. Furthermore, the number of brown adipocytes and the density of mitochondrial cristae increased in parallel with exposure to cold. These results demonstrate that adipocytes expressing UCP are present in adipose deposits considered as white fat. They suggest the existence of a continuum in rodents between BAT and WAT, and a great plasticity between adipose tissue phenotypes. The physiological importance of brown adipocytes in WAT and the regulation of UCP expression remain open questions.

Adipose Tissue↗

PubMed1991

Rat interscapular brown adipose tissue at different ages: a morphometric study.

Interscapular brown adipose tissue (IBAT) was studied in newborn and 1, 3, 5, 7, 13, 26, 52, 78 and 104-week-old rats maintained under standard laboratory conditions in order to define its morphological modifications and assess previous statements on an involution phase of IBAT after the first weeks of extrauterine life. Serial sections were analysed morphometrically to quantify the multilocular, the monolocular and the connective-vascular components of IBAT. Morphometry shows that the IBAT weight and volume progressively increase up to the twenty-sixth week of age, these figures remaining almost constant thereafter. The volume of the unilocular and connective components increased with age. The volume of the multilocular component increases up to the sixth month of age, and slightly reduces thereafter. The number of the multilocular adipocytes is almost constant from the third week up to the second year of life. Our results suggest that, in IBAT of adult animals, despite a slight prevalence of unilocular adipocytes, the number of multilocular cells is not reduced with respect to younger animals.

Adipose Tissue↗

PubMed1990

Characterization of different microenvironments at the surface of the frog's taste organ.

We used a panel of histochemical techniques to identify and characterize the cell-associated extracellular material at the surface of the frog's taste organ. We employed morphological and histochemical techniques using both the light microscope and the electron microscope. Results show that the apical, external aspect of cells reaching the surface of the taste organ is in close contact with a layer of amorphous material. The histochemical characteristics of this material vary according to the cell type with which it is in contact. Three different microenvironments can be identified at the surface of the frog's taste organ: type 1 microenvironment is associated with the superficial layer of mucus (secretory) cells; type 2 microenvironment characterizes the surface of the so-called wing cells, which reach the surface of the taste organ as thin laminae running among mucus cells; and type 3 microenvironment shrouds the free endings of putative taste cells and is rich in calcium and lipids. Type 2 and type 3 microenvironments fix peroxidase (a sapid macromolecule) with increasing affinity. We conclude that highly differentiated microenvironments exist at the surface of the frog's taste organ, and these could play a role in the chain of biological events leading to the taste sensation. Furthermore, characterization of the cell-associated, specific microenvironments can help clarify the role of the different cell types in the frog's taste organ.

Animals↗

PubMed1990

Morphometric evaluation of intracytoplasmic lipid in normal and pathological parathyroid glands.

The chief morphological criterion for classifying parathyroid glands as 'normal', 'suppressed', or 'activated' is the lipid content of the cytoplasm. In particular, cytoplasm lipid deposit is scanty in the active parathyroid cell, according to many authors. In this paper we present the results of a morphometrical study of ten normal parathyroid glands from patients undergoing thyroidectomy, 20 enlarged 'adenomatous' glands from patients with primary hyperparathyroidism, and 20 glands of normal size from the same hyperparathyroid patients. We aimed at assessing the content of intracytoplasmic lipid of secretory cells in all these conditions. The results show that secretory cells of adenomatous glands have less lipid than those from normal glands; however, there was considerable overlapping of the data in the two groups. The mean lipid content of cells in glands of normal size taken from hyperparathyroid patients was not significantly different from the mean value of normal cells, even when ultrastructural evidence of activation was present in the former. These data suggest that caution has to be exercised in assessing the functional status of parathyroid glands on the basis of lipid content of secretory cells, mainly when differentiating between adenoma and hyperplasia.

Cytoplasm↗

PubMed1990

Bile acids reversible effects on small intestinal permeability. An in vitro study in the rabbit.

To define the action of deconjugated bile acids on the small intestinal permeability in an in vitro system, we investigated the effects of chenodeoxycholic acid and ursodeoxycholic acid on the rate of transmural flux of lactulose in jejunal and ileal mucosa of rabbits, stripped of their muscle layers and mounted in Ussing chambers. In a series of experiments, tissue samples from small intestinal segments either exposed to bile acids or not also were examined by scanning and transmission electron microscopy to study the integrity of the tight junctions. Results show that chenodeoxycholate, starting at the concentration of 0.1 mM, enhanced in a dose-related manner the transepithelial flux of lactulose in the ileum. Both chenodeoxycholate (0.5 mM) and ursodeoxycholate (0.5 mM) significantly increased mucosal permeability to lactulose in jejunum and ileum; the effect of chenodeoxycholate was also shown to be reversible, as it completely disappeared within 40 min after its withdrawal and it did not result in permanent changes of epithelial transport function. Finally, the tight junctions appeared loosened by the addition of 1 mM chenodeoxycholate, suggesting that this is the major site of the transient bile acid increase of small intestinal permeability to compounds such as lactulose, having a molecular radius wider than 0.5 nm.

Animals↗