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Biomedical subjects

L Simonelli

Publications and source records attributed to L Simonelli.

At least 19 recordsLinked to original sources
PubMed2006

Small bowel intussusception: what is the role of laparoscopy?

Small bowel intussusception in adults is a rare surgical disease which almost always occurs as a complication of either benign or malignant lesion of the bowel that is working as a leading point. In adults, the surgical approach consists of the resection of the bowel involved to ensure the excision of the lesion below. The authors report a case of ileocecal intussusception occurred in a young woman, 35 years old, observed for abdominal pain and signs of small bowel occlusion. She underwent surgical resection of the ileocecal segment with laparoscopic approach. The authors discuss the feasibility of the laparoscopic approach in this rare surgical disease and its benefits in terms of patient's postoperative comfort and outcome.

Journal Article↗
PubMed2005

Role of extracellular matrix in regulation of staurosporine-induced apoptosis in breast cancer cells.

Autocrine and paracrine mechanisms modulate the synthesis and secretion of extracellular matrix (ECM); moreover, each component of the ECM is capable of modulating the synthesis and release of other ECM molecules. Therefore, the synthesis of ECM glycoprotein fibronectin and laminin was studied in the human breast cancer cell lines MCF7 and MDA MB 23, plated on different ECM. Our results showed that the cells plated on a fibronectin substrate increased laminin synthesis: this event correlated with an increase in alpha2 and alpha3 integrin subunits. Staurosporine-induced apoptosis was then analyzed in the cell lines plated on different ECM. Staurosporine treatment determined the apoptosis of 35 and 33% respectively of MDA MB 231 and MCF7; these values increased to 60 and 64% in cells plated on laminin, to 48 and 63% in cells plated on fibronectin and to 64 and 69% in cells plated on matrigel. Moreover, staurosporine treatment decreased bcl-2 expression in the cells plated on fibronectin and laminin. Yet, staurosporine treatment determined PARP cleavage and PARP partial disappearance when the cells were plated on matrigel. Finally, a partial loss of function mutant Ras protein that activated only Raf pathway, was expressed in MCF7, in order to identify whether the increase of apoptosis induced by extracellular matrix involved the Raf/MAP kinase pathway. The increase of apoptosis of the cells plated on matrigel suggested that the activation of the Raf pathway is probably involved in the decrease of survival on matrigel. These data demonstrate that the modification of ECM modulates the apoptotic process of breast cancer cells and suggest that it is worthwhile to dissect the role of ECM in the control of apoptotic process.

Apoptosis↗
PubMed2005

Squamous and adenosquamous cell carcinomas of the gallbladder.

Squamous and adenosquamous cell carcinomas (ASC and SCC) are rare subtypes of gallbladder cancer, traditionally considered more aggressive and with a poorer prognosis than adenocarcinoma. We report about two patients affected by an advanced squamous cell carcinoma of the gallbladder. Both had a large tumour in the gallbladder fossa region with infiltration of the liver. Surgical resection was radical in one, but palliative in the other. pTNM was T3 N0 M0, G3, R0 in the former and T3 N0 M0, G2 R1 in the latter. Patients died for local recurrence after 12 and 5 months, respectively. Natural history, clinical findings, prognosis and outcome of this rare gallbladder tumour are discussed on the basis of a review of the English literature. In conclusion, an aggressive and radical surgical treatment of advanced squamous and adenosquamous cell gallbladder carcinomas seems to be indicated for their low proclivity to distant spreading.

Aged↗
PubMed2004

[Lipoma, lipoma-like, atypical lipoma: case report].

Lipoma, generally considered as a benign neoplasia, may occur as liposarcoma lipoma-like or atipycal lipoma, especially when of huge dimension. Pathological features of lipoma and liposarcoma lipoma-like are similar: the pattern is characterized by fatty lobules, with fibrosus septa. The presence of vartiable amount of atipical cell with hyperchromatic, solitary or multiple nuclei is suggestive of liposarcoma lipoma-like or atypical lipoma. The clinical features of these lesions are high rate of local recurrence and a low risk to metastasize. Preoperative work up, ultrasounds and MR have a poor diagnostic value, and no imaging features are so specific to differentiate between lipoma and liposarcoma lipoma-like, except site and size. The surgical treatment of the liposarcoma lipoma-like and atypical lipoma and the postoperative therapy, when required, should be performed in specialized centers. Only the combined approach, surgery and radiotherapy, can result in prevention of local recurrence and malignant transformation. The Authors report two cases of liposarcoma lipoma-like admitted to their Institution and review the Literature.

Adult↗
PubMed1998

Advances in the understanding of malignant transformation of keratinocytes: an immunohistochemical study.

AIM: We set out to investigate the interactions between malignant transformation of keratinocytes, presence of oncoproteins and immunosurveillance in squamous cell carcinoma (SCC) and in a preneoplastic lesion, actinic keratosis (AK). METHODS: Samples of SCC, AK and normal skin (NS) were subjected to quantitative analysis using the following antibodies: anti-p53, Ki67, OKT6, OK-DR, B7/BB1, anti-CD54, anti-CD11, OKT3, OKT4, OKT8; positivity for ras-p21, EGFr and bcl-2 was evaluated by semiquantitative analysis. RESULTS: Oncoprotein alterations and increased keratinocyte proliferative activity were observed both in AK and SCC. The number of Langerhans cells (CD1a+ cells) was similar in the two lesions but lower in SCC compared to AK. The proportion of CD1a(+)-B7/BB1+ cells was slightly higher in AK and SCC than in NS. The Langerhans cells expressed the HLA-DR antigen in all groups. Values were highest in AK and NS, and quite low in SCC. Cytotoxic T lymphocytes were more numerous in SCC than in AK and NS. Interestingly, the total CD4/CD8 ratio was much lower in SCC than in AK and NS, which indicates an increase in the CD8+ subpopulation in samples of SCC. In the epithelia of SCC samples there were a considerable number of B7/BB1+ keratinocytes. CONCLUSIONS: We suggest that alterations in the immunodefence mechanisms have an important role in the transformation of AK into SCC, and that these changes affect not only lymphocytes, but also professional (i.e., Langerhans cells) and non-professional (i.e., keratinocytes) antigen presenting cells.

Aged↗
PubMed1997

An experimental study in X-ray spectroscopy of the zirconium (Ca-PSZ) - bone interface. Microanalytic evaluation of the osteogenetic response.

Ultrastructural difractometric and chemical evaluations of calcium partially stabilized zirconium (Ca-PSZ) implants were performed in an in vivo study on animals in order to evaluate its biological behaviour. The chemical-morphological investigations demonstrated the presence of an osteogenetic activity at the bone-biomaterial interface. The new-osteogenesis was preceded by the formation of a loose connective tissue around the implants. This mesenchymal-type tissue without a capsular organization, allowing modulation of the mechanical forces to which the implant is subject, could be considered a positive event in the osteogenetic process and not a sign of future failure of the implant. Finally, microanalytical investigations carried out on non-implanted and implanted Ca-PSZ tools suggested that the surface of this ceramic material does not undergo modification once it has been inserted in the biological environment (12 months).

Journal Article↗
PubMed1996

In vitro study of gingival fibroblasts from normal and inflamed tissue: age-related responsiveness.

The aim of this study was to characterize some phenotypic expressions of fibroblasts from the human oral mucosa. Gingival and lower forearm fibroblasts from young (20-30 years) and elderly (> 60 years) subjects were analyzed. Gingival fibroblasts were taken from donors with (P) and without (NP) periodontal disease, while skin biopsies were taken from healthy subjects. Cell proliferation was assessed by evaluating the cell multiplication coefficient (C.M.C.). The proliferation potential of gingival fibroblasts from elderly individuals with and without periodontopathy did not differ from that of young subjects in the same condition but differed significantly in the skin samples. Enzyme neutral endopeptidase (EC 3.4.24.11) (NEP) activity, studied as a possible marker of cell ageing, showed an age-related increase in human skin fibroblasts but not consistently in gingival fibroblasts from individuals with or without periodontal disease. Cell area and substrate adhesion were evaluated by morphometric analysis. There were no significant differences between elderly P and NP subjects, while significant differences were observed between young and elderly P subjects. In conclusion, proliferative capacity and NEP activity in gingival fibroblasts did not appear to be age-related, probably because their microenvironment is continually moistened by saliva, which continues to contain growth factors, notably EGF, even into senescence. Tissue reaction and repair are important clinical and therapeutic implications.

Adult↗
PubMed1995

Biochemical-morphological modifications of platelet membranes during pregnancy-induced hypertension.

A platelet (PLT) function modification has been reported in normal pregnancies compared with the nonpregnant condition and it has been hypothesized to play a central role in the pathogenesis of pregnancy-induced hypertension (PIH). The aims of the present study were (i) to evaluate the lipid composition, fluidity at different depths, transport functions, and ultrastructural features of the PLT membrane in PIH and (ii) to ascertain whether similar modifications may be determined by the state of pregnancy in comparison with the nonpregnant condition. The platelets of healthy pregnant women (HPW) showed: (i) an increase in Ca2+ ATPase activity, (ii) a decreased fluidity of the deeper site of the membrane, (iii) a reduced cholesterol concentration, with an increased ratio between unsaturated and saturated fatty acids; (iv) a decreased intramembranous particles (IMP) distribution factor (DF) of the plasma membrane E face in comparison with healthy nonpregnant women. When comparing women affected by PIH with HPW, we observed (i) reduced Na+/K+ ATPase activity and enhanced Ca2+ ATPase activity and intraplatelet calcium concentrations, (ii) an increased membrane fluidity, (iii) an increased cholesterol concentration and ratio between unsaturated and saturated fatty acids, (iv) a reduction of the IMP number and the DF. Pregnancy produces a deep modification of the platelet plasma membrane, and PIH produces a more pronounced alteration of the maternal platelets, which can be responsible for the observed modifications in placental blood flow and in the fetomaternal exchange.

Blood Platelets↗
PubMed1993

Osteoconduction exerted by methylpyrrolidinone chitosan used in dental surgery.

Surgical wounds from wisdom tooth avulsions were medicated with freeze-dried methylpyrrolidinone chitosan, a gel-forming resorbable biopolymer obtained from crab chitosan by chemical modification. Methylpyrrolidinone chitosan promoted osteoconduction and the space left after avulsion was filled with newly formed bone tissue, which conferred desirable mechanical and physiological characteristics to the healed would site. Morphological evidence obtained from biopsies confirmed the radiographic data. Methylpyrrolidinone chitosan was progressively depolymerized by lysozyme and was no longer detected 6 months after surgery. None of the 10 patients reported adverse effects over one year of observation.

Bone Regeneration↗
PubMed1993

Gingival fibroblasts "in vitro" and Down's syndrome.

Gingival fibroblast cultures from four patients with Down's Syndrome (DS) and periodontal disease were compared with four in vitro age-matched fibroblast cultures of handicapped subjects (ND) also affected by periodontitis. The extra copy of chromosome 21 could alter growth regulation and biochemical mechanisms, so we examined quantitatively some DS phenotypical aspects to detect possible differences from those of controls. The growth properties of gingival fibroblast cultures from DS patients were more elevated than their ND age-matched controls. There were no differences in plasma membrane polarization and in neutral endopeptidase activity. The succinate-cytochrome C reductase activity decreases in DS fibroblasts compared with ND. Our results outline the difficulties to in using fibroblast cultures as an in vitro system to study premature ageing Down's Syndrome.

Adult↗
PubMed1989

[Ultrastructural and immunoelectron microscopic study of the desmoplastic stroma in carcinoma of the breast].

Different collagen types (I, III, IV, V) were identified in breast carcinoma desmoplastic tissue by ultrastructural analysis and immunoelectronmicroscopy. Type V collagen is present as a 12 nm. fibril in the stroma, either adjacent to the basement membrane or concentrated around the thicker fibers. Myofibroblasts, fibroblasts and tumor cells can be its major producers. Its possible function as a bridge between different collagens can be utilized, with different finality, by the same cells that have produced it. Furthermore, type V collagen can be involved in tumor invasion of the stroma and in all directional movements of tumor cells, as already demonstrated for other extracellular matrix components.

Breast Neoplasms↗
PubMed1976

An ultrastructural analysis of chick embryonic skin development in vitro.

Behaviour of 6-day chick embryo thigh skin in vitro in two different nutrients was studied electron microscopically. In explants supported with chicken serum containing medium epithelium keratinized faster than and in a similar way to that in ovo, except for the absence of corpuscola cribriformia in pericytes. It did not in explants supported with chick embryo extract containing medium, but underwent a noticeable ultrastructural evolution, mainly of granular reticulum and Golgi complexes. In the two series of cultures mesenchyme presented the same ultrastructural characteristics, especially as far as collagen fibers were concerned. The above data rule out the suggested regulatory role of collagen fibers in epidermal differentiation and support a possible epidermal two-step differentiative process. They are discussed in relation to the general mechanisms implicated in skin evolution.

Animals↗