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Biomedical subjects

G Conti

Publications and source records attributed to G Conti.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Opposite effects of dehydroepiandrosterone on the growth of 7,12-dimethylbenz(a)anthracene-induced rat mammary carcinomas.

The effect of dehydroepiandrosterone (DHEA) (2 mg, twice daily p.o.) on the growth of the dimethylbenz (a) anthracene (DMBA)-induced mammary carcinoma was studied in intact and ovariectomized adult female rats. DHEA treatment stimulated the tumor growth in ovariectomized animals. Conversely, the tumors of intact rats treated with DHEA progressed to a lesser extent than those of intact untreated animals (p < 0.01). Plasma levels of DHEA were higher in DHEA-fed than in untreated animals (p < .01), whereas E2 concentrations were unchanged after DHEA administration. Estrogen receptor (ER) concentrations in tumor tissue of ovariectomized animals given DHEA were no different form those found in intact rats, whereas ER were undetectable in untreated ovariectomized rats. The data indicate that DHEA stimulates the growth of DMBA-induced mammary tumors in ovariectomized rats, while it reduces the tumor progression in intact animals.

9,10-Dimethyl-1,2-benzanthracene↗
PubMedDate not supplied

[Biocompatibility of the acetate in the dialysis fluid].

PURPOSE: Dialytic vasculopathy is a major morbidity and mortality risk factor in patients undergoing chronic dialysis treatment. Among the pathogenetic factors some are related to the uremic condition, others are due to biocompatible reactions to dialytic materials. Endothelial cells (EC) are the target of the mediators released during bioincompatible reactions, and the related effects could be considered the initial event eliciting the vasculopathy pathogenesis. Among the others, we focused our attention on the role played in this process by the inducible isoform of nitric oxide (NO) synthase (iNOS). In previous studies we demonstrated that bioincompatible membranes, as well as acetate-containing dialysis buffers stimulate iNOS gene expression and activity in endothelial cells in culture. In this study, we planned to evaluate the potential role of a new dialysis buffer in which acetate has been substituted with HCl as a stabilizer. METHODS: ECs were incubated for 12 h at 37 degrees C with different dialysis buffers: acetate (Acet), standard bicarbonate (Bic), acetate-free buffer (AF) and HCl-bicarbonate (BicHCl). We evaluated in reverse transcriptase polymerase chain reaction (RT-PCR) the gene transcription for iNOS, the NOS activity (as the production of H3 citrulline from H3 arginine by ionic exchange chromatography), EC proliferative (H3 thymidine incorporation) and pro-apoptotic rate (TUNEL analysis) and the nuclear translocation of the transcriptional factor NF-kappaB (EMSA). RESULTS: Acetate, even in the low concentration present in Bic was able to induce a significant iNOS gene transcription (results expressed as relative units and referred to basal values: Acet 1.9 +/- 0.01 fold increase, p<0.01; Bic 1.45 +/- 0.03 p<0.05; BicHCl 1.24 +/- 0.01; AF 1.17 +/- 0.02) and translation. Acetate at concentrations both of 3 mmoL and 38 mmoL (present in the bicarbonate buffer) significantly increased the enzymatic NOS activity vs unconditioned ECs: Acet 3.46 +/- 0.3, p<0.0005; Bic 1.69 +/- 0.2, p<0.005; BicHCl 1.24 +/- 0.15; AF 1.17 +/- 0.05. The EC proliferative index was significantly depressed by acetate containing dialysis buffers (unconditioned ECs 100%, Acet 38 +/- 15%, p<0.01; Bic 65 +/- 6%, p<0.05; AF 87 +/- 8%; BicHCl 75 +/- 6%). The percentage of apoptotic ECs was significantly increased by buffers contain-ing Acet vs BicHCl and AF. Finally, acetate at the concentrations present in Acet and Bic activated and promoted the nuclear translocation of the transcriptional factor NF-kappaB in ECs (p<0.01 vs unconditioned cells). CONCLUSIONS: The acetate-free dialysis buffers have better biocompatibility and potentially down-modulate the flogistic and sclerotic processes responsible for dialytic vasculopathy.

Acetates↗
PubMedDate not supplied

[Kidney transplantation in children].

Indications, procedures, complications, pharmacokinetics and outcomes of renal transplantation are different in children and in adults. Subjects <18 yrs old, are often included in a unique list as in Italy, benefiting from donors <15 yrs old, and the waiting time is reduced to <12 months in 71% of cases. The risk of thrombosis limits the use of donors <2 yrs and trans-plantation in infants <1 yr. The age at kidney transplantation is <5 yrs in 20-30% of children. In Italy living-related trans-plantation (LRT) is performed in 7% of cases, while in the USA it is more common (57%) and is often pre-emptive before entering dialysis (24%). Current therapy tends to reduce steroid treatment doses and, optimizing induction therapy with IL-2R inhibitors, using tacrolimus or mycophenolate or sirolimus. Transplanted patient survival is better in children than in adults (94-98% at 5 yrs). Infections, cardiovascular diseases and neoplasia induce 34, 15 and 12% of deaths, respectively, at 10 yrs; morbidity for infections and lymphoproliferative disease is increasing. Acute rejections declined from 70% in 1987 to 31% in 2002 in cadaveric transplantation (CT) and renal survival at 3 yrs increased from 50% in 1985 to 82% for CT and up to 92% in LRT. In adolescents (11-17 yrs old) renal survival is lower than in infants and in adults <65 yrs old. Renal losses are due to chronic transplant nephropathy (32%), vascular thrombosis (13%) and the recurrence of the original nephropathy (focal glomerulosclerosis up to 50%, membrano-proliferative glomerulonephritis up to 30%, and primary hyperoxaluria up to 90% if combined kidney-liver transplantation is not performed). Growth improves after transplantation particularly in children <5 yrs, while it is not completely satisfactory in adolescents. Overall, results indicate that kidney transplantation in children has very much improved and will offer in the near future even more favorable outcomes.

Child↗
PubMedDate not supplied

Epidermal growth factor stimulates colony formation and non-neuronal marker protein expression by human neuroblastoma in methylcellulose culture.

Growth of the human neuroblastoma IMR-32 in methylcellulose culture was studied. The number of colonies was proportional to the number of seeded cells in all conditions tested: control cultures (CT) and test cultures with epidermal growth factor (EGF), hydrocortisone (HC), combined EGF/HC, fibroblast growth factor (FGF) or nerve growth factor (NGF). A portion of IMR-32 cells formed colonies and all factors were without effect when tested individually. In contrast, the combination of EGF/HC at low cell densities enhanced the number of colonies two-fold as compared to controls. Differentiation in IMR-32 colonies was examined by immunocytochemical detection of cell specific marker proteins. As determined by staining with different markers, at least two cells subpopulations could be established within the same colony. One of them expressed NSE (neuron specific enolase) and was designated as neuronal. The other subpopulation was called non-neuronal since it consisted of vimentin and S-100 protein positive cells which were considerably enhanced in the presence of EGF or EGF/HC. In vitro, the IMR-32 neuroblastoma cell line contains pluripotent stem cells from which are derived distinct phenotypes sensitive to different extrinsic factors. Increasing time in culture enhanced neuronal differentiation. EGF, on the other hand, targeted preferentially the non-neuronal phenotype, and stimulated colony formation and its differentiation.

Antigens, Neoplasm↗
PubMedDate not supplied

Microcinematographic and electron microscopic study of the death of human tumor cells induced by histiocytic cells.

The cells from a malignant fibrous histiocytoma were enzymatically isolated and cultured in vitro. The cultures were observed by microcinematography and with an electron microscope after fixation and embedding. The interactions between histiocytic and tumor cells resulted in tumor cell death. The microcinematographic study revealed that filiform projections of the histiocytic cell protrude toward the tumor cell surface making contacts for varying periods of time. The tumor cell then contracts and almost simultaneously some granules (lysosomes?) appear in the tumor cell cytoplasm. These granules eventually fuse with each other thus increasing in volume. The resulting granulation heads for the periphery of the tumor cell at a site previously touch by a projection of a histiocytic cell; at this site the membrane bursts and the tumor cell dies leaking amorphous cytoplasmic material. Before bursting the tumor cell does not show any noticeable morphological changes.

Cell Survival↗
PubMedDate not supplied

[Wolf-Hirschhorn syndrome].

We refer about two children with Wolf-Hirschhorn's syndrome or syndrome with partial deletion of short arm of chromosome number 4. The diagnosis was possible with an accurate estimation of phenotype. Cytogenetics examination showed the chromosomal aberration typical for this syndrome.

Child↗
PubMedDate not supplied

[Cells affected by apoptosis in effusions of tumor origin in man].

The cells from 3 human effusions of tumoral origin (adenocarcinoma) were observed by light and transmission electron microscopy. The presence and the type of cells undergoing apoptosis were studied. Among the different cell types present in these effusions, only some lymphocytes, macrophages and eosinophils (cells concerned in cell-mediated tumor immunity) are affected by the morphological changes of apoptosis. We did not find, as other authors did, tumor cells or other cell types (mesothelial cells, histiocytes, other granulocytes) showing apoptic alterations. The authors conclude that this peculiar morphological type of cell death affects the effector cells of the cell-mediated tumor immunity being at the end of their life-span.

Adenocarcinoma↗
PubMedDate not supplied

Clinical features, scintiscan characteristics and X-ray progression of late onset rheumatoid arthritis.

The clinical features, serology behaviour, scintiscan characteristics and the degree of X-ray progression according to the disease duration were compared in two RA groups with a disease onset after 65 years of age (LORA) and before 65 (EORA) respectively. No differences emerged in either the clinical findings or in the scintiscan picture. A sub-group of LORA showed acute flares of the illness presenting with very high ESR values and high fever. The erosive index (EI) evaluated in three areas (carpal-bone and wrist, MCP and PIP joints) revealed an undistinguishable degree of X-ray damage either in seropositive or seronegative patients, whereas seropositive EORA fared clearly worse than seronegative ones. A prospective study in two small sub-groups of LORA and EORA revealed a progression of X-ray erosions despite second line drug treatment in both groups, especially in LORA.

Adult↗