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Biomedical subjects

E Ottaviani

Publications and source records attributed to E Ottaviani.

At least 73 records · Page 4Linked to original sources
PubMed1998

Naltrexone suppresses the rejection of cardiac tissue transplantation.

The present study demonstrates the following: 1. Transplantation of cardiac tissue induces an inflammatory response that ultimately leads to the rejection of the tissue by the host within 9 days; 2. Treatment with the opiate antagonist, naltrexone, significantly increased the survival of the transplanted cardiac tissue to 13 days, suggesting the involvement of opioid signaling molecules in tissue rejection; 3. In further experiments it was demonstrated that in mixed lymphocyte populations from different mice, the DNA synthesis inhibitor, mitomycin C, reduced the lymphocyte proliferative response as did naltrexone; 4. Mice injected with naltrexone for 10 days and given concanavalin A exhibited a suppressed spleen lymphocyte proliferative response compared to controls. Taken together, these data suggest that endogenous opioid signals not only activate immunocytes, but also stimulate DNA synthesis.

Analysis of Variance↗
PubMed1998

The neuro-immunological interface in an evolutionary perspective: the dynamic relationship between effector and recognition systems.

The evolutionary perspective indicates that an immune-neuroendocrine effector system integrating innate immunity, stress and inflammation is present in invertebrates. This defense network, centered on the macrophage and exerting primitive and highly promiscuous recognition units, is very effective, ancestral and appears to have been conserved throughout evolution from invertebrates to higher vertebrates. It would seem that there was a "big bang" in the recognition system of lower vertebrates, and T and B cell repertoires, MHC and antibodies suddenly appeared. We argue that this phenomenon is the counterpart of the increasing complexity of the internal circuitry and recognition units in the effector system. The immediate consequences were a progressive enlargement of the pathogen repertoire and new problems regarding self/not-self discrimination. Probably not by chance, a new organ appeared, capable of purging cells able of excessive self recognition. This organ, the thymus, appears to be the result of a well known evolutionary strategy of re-using pre-existing material (neuroendocrine cells and mediators constituting the thymic microenvironment). This bricolage at an organ level is similar to the effect we have already described at the level of molecules and functions of the defense network, and has a general counterpart at genetic level. Thus, in vertebrates, the conserved immune-neuroendocrine effector system remains of fundamental importance in defense against pathogens, while its efficiency has increased through synergy with the new, clonotipical recognition repertoire.

Animals↗
PubMed1998

Characterization of Cyprinus carpio brain nitric oxide synthase.

Nitric oxide synthase (NOS) activity is found both in soluble and in particulate fractions of the carp brain. The Km values for arginine are 2.8+/-0.5 and 3.3+/-0.4 microM for the soluble and particulate fractions, respectively. K for NG-monomethyl-L-arginine inhibitor are 2.6+/-0.5 and 2.9+/-0.6 microM, and activation energy for the breakdown of the substrate-enzyme complex 8120+/-710 and 4620+/-450 cal per mole. Carp enzyme shows higher affinity than rat NOS for Ca2+ and for the competitive inhibitor 7-nitroindazole.

Animals↗
PubMed1998

In situ localization of ACTH receptor-like mRNA in molluscan and human immunocytes.

Adrenocorticotropin hormone (ACTH) receptor-like messenger RNA was localized in molluscan hemocytes and human peripheral blood mononuclear cells by in situ hybridization using a digoxigenin-labelled bovine complementary DNA probe. These findings suggest that the ACTH receptor gene has been highly conserved during evolution. Moreover, these data represent further support for a relationship between the immune and neuroendocrine systems in invertebrates, as documented in our previous studies.

Animals↗
PubMed1998

PDGF and TGF-beta induce cell shape changes in invertebrate immunocytes via specific cell surface receptors.

The presence of PDGF receptor-alpha- and -beta- and TGF-beta-receptor (type II)-like molecules on the plasma membranes of the immunocytes of the mollusc Mytilus galloprovincialis was demonstrated by an immunocytochemical procedure. Furthermore, the present study provides evidence that PDGF-AB and TGF-beta1 provoke cell shape changes in immunocytes via interactions with the respective receptors and that these extracellular signals are transduced along the phosphoinositide signaling pathway.

Animals↗
PubMed1998

Interactions of signaling pathways in ACTH (1-24)-induced cell shape changes in invertebrate immunocytes.

ACTH (1-24) induces cell shape changes in the immunocytes of the bivalve mollusc, Mytilus galloprovincialis. Using computer-assisted microscopic image analysis, we have found that the G protein antagonist suramin sodium, the adenylate cyclase inhibitor 2',5'-dideoxyadenosine, and the protein kinase inhibitor staurosporine inhibit this effect. The highly specific inhibitors H-89 (for protein kinase A) and calphostin C (for protein kinase C) only inhibited partially the morphological alterations. In contrast, the simultaneous action of H-89 and calphostin C completely blocked these changes. The above findings indicate that ACTH (1-24) induces cell shape changes in molluscan immunocytes via adenylate cyclase/cAMP/protein kinase A pathway, as well as the activation of protein kinase C.

Adenylyl Cyclase Inhibitors↗
PubMed1998

A new theory on the common evolutionary origin of natural immunity, inflammation and stress response: the invertebrate phagocytic immunocyte as an eye-witness.

Data in favor of the hypothesis of the common evolutionary origin of natural immunity inflammation and stress response are presented. These phenomena seem to be mediated by a common pool of molecules (POMC-derived peptides, cytokines, biogenic amines, glucocorticoids, and nitric oxide). Macrophages are able to release all the above mentioned molecules. They play a primary role in defence mechanisms. Thus, we argue that this cell can be considered the eye-witness of the common evolutionary origin of the immune and neuroendocrine systems.

Animals↗
PubMed1998

Presence of immunoreactive corticotropin-releasing hormone and cortisol molecules in invertebrate haemocytes and lower and higher vertebrate thymus.

Corticotropin-releasing hormone- and cortisol-like molecules are present in the haemocytes of different molluscan species and in the epithelial cells, interdigitating cells and macrophages - but not in the lymphocytes - of fish, frog, chicken and rat thymus. Taking into account the fact that other pro-opiomelanocortin-derived peptides, such as adrenocorticotropin hormone, are present in the haemocytes and thymus of the same species, these results complete the list of stress mediators present in molluscan haemocytes and further support the hypothesis that, although the prototype stress response we have demonstrated in invertebrates is concentrated in a single cell, i.e. the haemocyte, it is similar to the response seen in vertebrates. Moreover, the data presented here are compatible with the hypothesis that an evolutionary, conserved stress response can occur locally with a single organ, e.g. the thymus, in which all the main mediators of this biological response, such as corticotropin-releasing hormone, adrenocorticotropin hormone and glucocorticoids, are present. The implications of these findings for the physiology of thymus and stress response may be far reaching.

Animals↗
PubMed1998

Autologous peripheral blood stem cell transplantation in acute myeloblastic leukaemia and myelodysplastic syndrome patients: evaluation of tumour cell contamination of leukaphereses by cytogenetic and molecular methods.

We evaluated 18 acute myeloblastic leukaemia (AML) and myelodysplastic syndrome (MDS) patients with abnormal karyotype at diagnosis who underwent peripheral blood stem cell (PBSC) transplantation. To evaluate the presence of residual tumour cells, bone marrow (BM) samples and PBSC collections were analysed by cytogenetics and in selected cases also by fluorescence in situ hybridisation (FISH) and molecular studies. All patients were considered to be in morphologic and cytogenetic complete remission (CR) at the time of mobilisation. Seven patients showed neoplastic cells in PBSC harvest and/or BM specimen before reinfusion. Cytogenetic studies revealed contamination in apheretic collections in one patient only, while three patients had BM but not PBSC contamination. Three more patients had leukaemic cells both in the BM and PBSC. All but one (with only BM contamination) of these patients relapsed within 9 months. However, five more patients relapsed after transplantation: in four cases there was no cytogenetic sign of contamination either in PBSC or BM cells and in one case no molecular evidence was revealed either. This study suggests that, whereas the presence of leukaemic cells in autologous grafts correlates with a poor prognosis, the lack of detection of tumour cells is not always predictive of long-term disease-free survival. More importantly, PBSC collections from AML patients are not contaminated by leukaemic cells if the BM is disease-free.

Adult↗
PubMed1998

Inv(16) acute myeloid leukemia cells show an increased sensitivity to cytosine arabinoside in vitro.

Karyotype represents the major independent prognostic factor for response and remission duration in acute leukemia. In particular, it has been reported that acute myeloid leukemia (AML) patients with inv(16) abnormality show a better prognosis, especially in case of treatment with high-dose Ara-C (HD Ara-C) containing regimens. In this study we aimed at testing whether leukemic cells from patients showing the inv(16) were more sensitive to Ara-C in vitro, compared to AML blasts from patients with normal karyotype or chromosomal abnormalities other than t(15;17) or t(8;21). We analyzed blast cells from 30 patients who were diagnosed and treated in our institution. The IC50 of Ara-C, as tested by the XTT colorimetric assay, was significantly lower in cases with inv(16) (18.5+/-15.88 micromol/l vs. 38+/-14.6 micromol/l,in cases with other abnormalities, p=0.01). This result was confirmed by a higher incorporation of [3H]-Ara-C into DNA (p=0.02 and p=0.001 compared to samples with normal and abnormal karyotype, respectively). All the same, Ara-C induced apoptosis was significantly increased in cells from patients with inv(16). Our data suggest a possible interaction between the molecular background of inv(16) and a modification of intracellular metabolism of Ara-C, and could thus provide a rationale for HD-Ara-C-based schedules for patients with inv(16) AML.

Acute Disease↗
PubMed1998

Secretion of apoB- and apoA-I-containing lipoproteins by chick kidney.

Previous studies showed that chick kidney is a site of synthesis of apolipoprotein (apo) B(B-100) and A-I. Aims of the present study were: a) to compare apoB and apoA-I production in chick kidney and liver; b) to investigate whether kidney apolipoproteins were secreted as constituents of lipoproteins; and c) to define the cellular sites of renal apolipoprotein synthesis. Kidney and liver slices taken from the same animals were incubated with 35S-labeled amino acids and radioactive apoB and apoA-I were immunoprecipitated from cell homogenate and incubation medium. The percentage of total protein radioactivity incorporated into cell plus medium apoB and apoA-I was 0.23+/-0.08 and 0.19+/-0.11 in kidney and 0.38+/-0.05 and 0.38+/-0.07 in liver, respectively (P < 0.05 kidney vs. liver). 35S-labeled medium lipoproteins were separated by density gradient ultracentrifugation and three major classes corresponding to VLDL + IDL, LDL, and HDL were identified. Most of the apoB secreted by the liver was found in VLDL, IDL, and LDL whereas kidney apoB was found in VLDL, LDL and "light" HDL (d 1.070-1.130 g/ml). In both hepatic and renal lipoproteins apoA-I was found not only in HDL but also in the other lipoproteins. Immunohistochemical analysis of kidney sections showed that apoB and apoA-I were present almost exclusively in the epithelial cells of proximal and distal convoluted tubules. Thus apoB and apoA-I synthesized by the epithelial cells of the proximal and distal convoluted tubules of chick kidneys are secreted as constituents of lipoprotein particles floating within the density range of plasma lipoproteins. These observations suggest that in the chick, the kidneys may contribute to the plasma lipoprotein pool.

Amino Acids↗
PubMed1998

Detection of bcr-abl transcript in chronic myelogenous leukemia patients by reverse-transcription-polymerase chain reaction and capillary electrophoresis.

BACKGROUND AND OBJECTIVE: Capillary electrophoresis (CE) has become an attractive alternative to SLAB gel analysis for direct and accurate detection of amplified product, and a few cycles of polymerase chain reactions (PCRs) could be sufficient for both quantitative and qualitative analysis. We try to assess: 1) whether CE could be a practical, non-isotopic method for direct detection of the presence of amplified bcr-abl obtained by a reverse transcription (RT)-PCR (qualitative analysis) and 2) whether it is possible to quantify PCR products using a competitive RT-PCR measuring peak areas of CE electropherograms (quantitative analysis). DESIGN AND METHODS: The two types of bcr-abl chronic myelogenous leukemia (CML) associated transcript products were generated by RT-PCR (qualitative analysis) from 1 microgram of total RNA extracted from bone marrow samples of 34 CML patients at diagnosis (median age 47.5; range 18-65; median Sokal's score 0.9; range 0.53-2.78). The PCR products were analyzed by SLAB-gel electrophoresis (SGE) on 2% agarose gels and by CE (128 runs; median 3.3 times for each sample). Furthermore, we assessed the amount of PCR product (quantitative analysis) by a competitive RT-PCR approach and by CE (bcr-abl transcripts were expressed as transcript per microgram of total RNA examined). RESULTS: CE separation of PCR products obtained by qualitative RT-PCR showed baseline resolution for the two peaks corresponding to the two types of bcr-abl junctions: the b2-a2 type (343 base pairs, 10 patients) was revealed at 9.33 min [standard deviation (SD) = 0.1] and the b3-a2 type (418 base pair, 24 patients) at 10.03 min (SD = 0.25). By quantitative analysis we found that there is great interpatient variability in bcr-abl expression at diagnosis: the median value of the amount of bcr-abl transcript was 78,000 bcr-abl transcript/microgram total RNA ranging from 17,300 to 750,000. The amount of bcr-abl transcript at diagnosis was related to the number of blast cells (mean value 128,859 vs. 331,722 in patients with 0% blast cells and > 1% blast cells, respectively; p = 0.004) and Sokal's score (mean value 156,865 vs. 408,800 in patients with Sokal's score < 0.8 and > 1.2, respectively; p = 0.003). INTERPRETATION AND CONCLUSIONS: Our results confirm that CE analysis offers greater resolution and enhanced sensitivity for detection and quantification of bcr-abl PCR product in the study of this leukemia. Qualitative analysis by CE of bcr-abl product provides a rapid technique (less than 20 min) for the analysis of subnanogram amounts of DNA fragments. CE run times are short, the capillary can be re-used and full automation may be feasible with data acquisition by a computer-controlled step. Competitive/quantitative analysis of bcr-abl as analyzed by CE allowed fewer reactions and more precise quantification.

Adolescent↗
PubMed1998

Long-term disease-free acute promyelocytic leukemia patients really can be cured at molecular level.

The characteristic t(15;17) translocation involving chromosomes 15 and 17 is specifically associated with both the common and the variant subtypes of acute promyelocytic leukemia (APL) (M3 according to FAB classification). At the molecular level, it fuses genes encoding PML on chromosome 15 and the nuclear retinoic acid receptor-alpha (RAR alpha) on chromosome 17. The subsequent expression of PML/RAR alpha fusion mRNA provides a potential molecular marker that can be detected in leukemic cells taken from patients with APL. Using PML and RARa sequence specific primers, reverse transcription-polymerase chain reaction (RT-PCR) assays have been developed for detection of PML/RAR alpha transcript in leukemic cells obtained from patients; these RT-PCR assays are more sensitive than conventional cytogenetic analysis.

Adolescent↗
PubMed1998

Disappearance of PML/RAR alpha acute promyelocytic leukemia-associated transcript during consolidation chemotherapy.

BACKGROUND AND OBJECTIVE: Acute promyelocytic leukemia (APL) (M3 according to FAB classification) is a subtype of acute myelogenous leukemia characterized by a specific t(15;17) (q22;q12) chromosomal translocation. The majority of APL patients achieve morphologic remission after induction chemotherapy. They can be followed from this point by cytogenetic and molecular analysis of the persistence of the PML/RAR alpha transcript. In order to determine the influence of successive courses of consolidation chemotherapy on clinical and molecular outcome, APL patients treated with all-trans retinoic acid (ATRA) and chemotherapy (AIDA-GIMEMA-LAP0493 protocol) were investigated. DESIGN AND METHODS: Twenty-four APL patients (pts) (15 males; 9 females) were studied by RT-PCR and cytogenetic analysis at diagnosis, after induction chemotherapy, at each point after any of three consolidation courses, and every 3 months during the first years of maintenance therapy. The median follow-up was 24 months (mths) (range 7-40 mths). RESULTS: All pts achieved hematologic remission after induction chemotherapy. Our results demonstrate that the majority (87%) of APL patients were still molecularly positive for the APL associated transcript after induction chemotherapy, while the majority (80%) of APL patients became PCR-after the second consolidation chemotherapy. INTERPRETATION AND CONCLUSIONS: The role of the third consolidation chemotherapy course in converting patients with persistent molecular evidence of disease from PCR+ to PCR- was minimal. We confirm the validity of molecular follow-up after single courses of chemotherapy in monitoring the role of molecular remission.

Adolescent↗
PubMed1998

Role of autologous bone marrow transplantation as consolidation therapy in acute promyelocytic leukemia patients in complete remission.

Autologous bone marrow transplantation (ABMT), which consents a low mortality rate, has been proposed as an alternative approach to maintenance chemotherapy in patients with acute promyelocytic leukemia (APL) in first complete remission irrespective of the patients' molecular status. Sixteen patients with acute APL in complete remission were submitted to ABMT and were analyzed for the presence of the PML-RARa fusion gene by reverse transcription-polymerase chain reaction (RT-PCR). Our study demonstrated that continued positivity of PCR analysis before ABMT could predict subsequent relapse in patients who undergo un-purged ABMT procedures.

Adolescent↗
PubMed1997

Effect of PDGF and TGF-beta on the release of biogenic amines from invertebrate immunocytes and their possible role in the stress response.

PDGF-AB and TGF-beta 1 intervene in molluscan stress response, the former inhibiting and the latter inducing the release of norepinephrine and epinephrine from hemocytes. These amines are down-regulated even when TGF-beta 1 is added to hemolymph pre-incubated with PDGF-AB. The opposite behaviour is observed if the growth factors are reversed. The dopamine response is not affected in either case, even after the addition of CRH or ACTH. After pre-incubation with PDGF-AB or TGF-beta 1 in the presence of CRH or ACTH, norepinephrine and epinephrine release falls. These findings suggest that when the interaction is between growth factors, the order of combination is crucial, while in cases where the interaction is between growth factors and other peptides, such as CRH and ACTH, the order is of no importance.

Adrenocorticotropic Hormone↗
PubMed1997

Reduction of heat-shock protein-70 after prolonged treatment with retinoids: biological and clinical implications.

Heat shock proteins (HSPs) are a group of highly conserved polypeptides involved in cellular response to heat or other physical or chemical stresses. It has been recently reported that HSPs could play a role in cellular differentiation. In this study we have evaluated, by a cytofluorimetric method, the presence of HSP-70 in HL-60 cells during treatment with all-trans retinoic acid (ATRA), 9-cis retinoic acid (9-cis RA), and 13-cis retinoic acid (13-cis RA). After 1 and 3 days of incubation at 10(-7) M, HSP-70 did not show any variation compared to control; prolonging the exposure, together with the appearance of cellular differentiation along the granulocytic pathway and apoptosis, a progressive decrease of HSP-70 was observed that, after 8 days of treatment, was reduced by 40% with ATRA and by 28% with 9-cis RA compared to untreated samples, while only minimal changes were evident by incubating the cells with 13-cis RA. Reduction of HSP-70 was not associated with decreased protein synthesis, as demonstrated by [3H] leucine incorporation. Double labeling with propidium iodide showed a decrease in HSP-70 in all the phases of the cell cycle concomitant with a reduced percentage of cycling cells in ATRA-treated samples. Dot blot and Northern blot analysis demonstrated no change in HSP-70 mRNA after retinoid treatment, thus suggesting a post-transcriptional regulation of the phenomenon. This reduced production of HSP-70 caused by ATRA and by 9-cis RA, though to a lesser extent, could render the cells more sensitive to cytotoxic agents and could provide the rationale for the efficacy of ATRA + chemotherapy combinations.

Alitretinoin↗