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Biomedical subjects

G Avanzi

Publications and source records attributed to G Avanzi.

At least 19 recordsLinked to original sources

Alpha-linolenic acid and cardiovascular diseases omega-3 fatty acids beyond eicosapentaenoic acid and docosahexaenoic acid.

Over the last decades, an increasing body of evidence has been accumulated on the beneficial effect of polyunsaturated fatty acids both in primary and secondary prevention of cardiovascular diseases. However, the vast majority of the studies has been performed on long-chain polyunsaturated fatty acids, such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and not on their biochemical precursor, alpha-linolenic acid (ALA). Actually, ALA has some other beneficial effects apart from the known antiarrhythmic effect. In fact, ALA has a strong inhibitory effect on omega-6 metabolic pathway. An adequate daily intake of ALA shifts metabolic pathway to EPA, so favoring the formation of products with a predominant antiaggregating and vasorelaxing action, with respect to eicosanoids with a predominant thrombotic effect. Some important evidences have been raised on the association between ALA and cardiovascular mortality. Indeed, dietary ALA has been associated with a lower rate of fatal and nonfatal coronary events. Hence, major scientific associations published nutritional guidelines including a specific recommendation for ALA.

Cardiovascular Diseases↗

Acute megakaryoblastic leukemia: experience of GIMEMA trials.

The objective of the study was to evaluate the incidence, characteristics, treatment and outcome of acute megakaryoblastic leukemia (AMeL) in patients enrolled in GIMEMA trials. Between 1982 and 1999, 3603 new consecutive cases of AML aged over 15 years were admitted to GIMEMA trials. Of them, 24 were AMeL. The incidence of AMeL among AML patients enrolled in GIMEMA trials was 0.6% (24/3603). Diagnosis was based on morphological criteria. Out of 11 cytogenetic studies performed two presented chromosome 3 abnormalities. Twelve patients (50%) reached a CR, five (21%) died in induction and seven (27%) were unresponsive. The median duration of CR was 35 weeks (range 10-441). Seven patients underwent transplantation procedures (1 BMT, 4 aBMT, 2 aPBSCT). Four patients died in CR due to chemotherapy-related complications. Comparing the CR rate between AMeL and the other cases of AML enrolled in GIMEMA trials, no differences were observed. These results were mirrored for different age groups. The median survival was 40 weeks. At present, after a follow-up of a minimum of 2 years, only two patients are alive in CR, all the others having died. A 5-year Kaplan-Meier curve shows a disease-free survival of 17% and an actuarial overall survival of 10%. AMeL is a rare form of AML. The CR duration and the overall survival in this group of patients are very poor, even if similar to those observed in other AML. Furthermore, a high number of deaths in CR were observed. On the basis of these data, a specific therapeutic approach, possibly with innovative treatments, should be evaluated.

Adolescent↗

4-Aminobiphenyl-DNA adducts and p53 mutations in bladder cancer.

Epidemiologic studies have suggested that smokers of air-cured tobacco (rich in arylamines) are at higher risk of bladder cancer than smokers of flue-cured tobacco. The risk has been shown to be modulated by the N-acetyltransferase genotype. We analyzed the biopsies of 45 patients with bladder cancer. p53 mutations were sought by direct sequencing, and 4-aminobiphenyl-DNA adducts were measured by negative ion gas chromatography-mass spectrometry. 4-Aminobiphenyl-DNA adducts were higher in smokers of air-cured tobacco and in current smokers, but no relationship with the number of cigarettes smoked was found. Adducts were higher in more advanced histologic grades of tumors. No pattern was evident for p53 mutations. Seven of 9 mutations occurred in grade 3 tumors. No association was found between 4-ABP adducts and GSTM1 or NAT2 genetic polymorphisms.

Adult↗

Anti-GM1, anti-central myelin proteins, and anti-cardiolipin autoantibodies during plasma-exchange in Guillain-Barré syndrome (GBS).

We measured the autoantibodies to GM1, central myelin proteins, and cardiolipin in 30 GBS patients using sensitive ELISA and Western blot techniques. The sequential modifications of titers during plasma-exchange (PE) and at follow-up were investigated in 15 patients. In pretreatment sera, we found significantly increased antibody titers to GM1 (37% of the patients), central myelin proteins (28%), and cardiolipin (21%). Seventeen patients out of 29 (58%) presented increased IgG or IgM antibody to at least one of the antigens considered as compared to 10 out of 70 controls (14%, P = 0.00001). By Western blot, IgG or IgM antibodies reactive with the triton insoluble fraction of central myelin were observed in 19 out of 28 GBS patients (67%). The follow-up measurements during and after PE showed a declining autoantibody titer in 10 out of 15 patients. However, in the remaining 5 GBS patients, we observed a persistently elevated titer or an increase from baseline values occurring during or after PE and reaching a peak. In 2 of the 5 patients, the titer peak preceded a clinical re-exacerbation. The presence of a persistently elevated or an increasing autoantibody titer during treatment with PE merits further investigation and may help to clarify the pathogenesis of GBS and improve its treatment.

Adolescent↗

Role of prolactin in the in vitro development of interleukin-2-driven anti-tumoural lymphokine-activated killer cells.

Exogenous prolactin (PRL) has been shown to synergize with low-dose interleukin-2 (IL-2) and induce the proliferation and lymphokine-activated killer (LAK) maturation of natural killer (NK) cells. PRL itself can also generate LAK activity. Here we show that its local production occurs during, and is necessary for, LAK development. IL-2-stimulated peripheral blood mononuclear cells (PBMC) and purified NK cells were exposed to anti-human (h)PRL antiserum, and residual LAK activity was measured on day 7 against the promyelocytic leukaemia cell line HL-60. Inhibition of LAK activity was much more evident in PBMC compared with NK cell cultures (47% decrease. P - 0.013 and 18.5% decrease. P = 0.048, respectively). Up-modulation of a 32S-methionine-labelled 27,000 MW protein was detected in the lysates and supernatants of IL-2-stimulated PBMC immunoprecipitated with an anti-PRL antiserum. By contrast, the cytoplasmic PRL immunoreactivity observed in freshly isolated NK cells and in IL-2-stimulated, but not unstimulated, NK cell cultures was not associated with PRL gene activation, and can thus be referred to internalized PRL. Preferential re-uptake of externally derived PRL by IL-2-stimulated NK cells was also indicated by up-modulation of the PRL receptor. These data, as a whole, indicate that the PRL promotion of LAK differentiation is mainly mediated by paracrine secretion, with a minor contribution from internalized PRL.

Cell Differentiation↗

Haemorheological changes in mixed cryoglobulinaemia during apheresis treatment.

Thirty-four patients affected by mixed cryoglobulinaemia have been submitted to treatment by apheresis (plasma exchange or double cascade filtration). The authors have monitored clinical, laboratory and, above all, haemorheological changes following therapy. The final results have shown mainly a reduction of plasma viscosity and consequently an improvement of the haemorheology of the affected organs. In conclusion, apheresis may be considered a successful therapy in patients with severe renal or neurological diseases due to mixed cryoglobulinaemia.

Blood Viscosity↗

A case of idiopathic myelofibrosis with alloimmunization to HLA-identical platelet transfusions not responsive to antibody absorption over protein-A columns.

A case of idiopathic myelofibrosis has been treated with HLA-identical platelet apheresis concentrates. After a short period the patient also developed refractoriness to the haploidentical siblings. Protein A columns were used to absorb the platelet antibodies with no result. Now two apheresis platelet concentrates are used every month, crossmatched negative products produce good results maintaining cell counts between 20 and 30 x 10(9)/L. The immune mechanism involved is difficult to understand.

Adult↗

The protein encoded by a growth arrest-specific gene (gas6) is a new member of the vitamin K-dependent proteins related to protein S, a negative coregulator in the blood coagulation cascade.

A set of growth arrest-specific genes (gas) whose expression is negatively regulated after serum induction has previously been described (C. Schneider, R. M. King, and L. Philipson, Cell 54:787-793, 1988). The detailed analysis of one of them, gas6, is reported here, gas6 mRNA (2.6 kb) is abundantly expressed in serum-starved (48 h in 0.5% fetal calf serum) NIH 3T3 cells but decreases dramatically after fetal calf serum or basic fibroblast growth factor stimulation. The human homolog of gas6 was also cloned and sequenced, revealing a high degree of homology and a similar pattern of expression in IMR90 human fibroblasts. Computer analysis of the protein encoded by murine and human gas6 cDNAs showed significant homology (43 and 44% amino acid identity, respectively) to human protein S, a negative coregulator in the blood coagulation pathway. By using an anti-human Gas6 monospecific affinity-purified antibody, we show that the biosynthetic level of human Gas6 fully reflects mRNA expression in IMR90 human fibroblasts. This finding thus defines a new member of vitamin K-dependent proteins that is expressed in many human and mouse tissues and may be involved in the regulation of a protease cascade relevant in growth regulation.

3T3 Cells↗

Therapeutic plasma adsorption. A review.

Alternative techniques to the traditional plasma exchange are emerging in clinical practice for the treatment of different pathological conditions, particularly autoimmune diseases. Filtration is a technique used to separate blood cells from plasma, which may be further "treated" with other filters or columns. The case for cascade filtration and absorption onto a column is becoming stronger and stronger and the patient population is increasing. Alongside the "historical" techniques of adsorption onto a column, new systems (pairs of self-regenerating columns) and new products (columns with dextran sulphate, tryptophane, anti-human lipoprotein antibodies) are now available. Protein A in particular seems to open up new horizons; in therapeutic plasmapheresis, there are two versions, one Swedish and the other American, based on different theoretical premises and obtaining different results, with different biocompatibilities but good clinical results.

Adsorption↗

Plasma exchange in systemic lupus erythematosus. Experience in thirty-seven patients.

Thirty-seven (37) SLE patients submitted to therapeutic plasmapheresis were examined. The results were good in the active stage of the disease. Various types of antibody, anti-DNA, anti nucleus, anti-cardiolipine, I.C. (Clq and C3d) were removed. The values of IgG, coagulation factors, creatinine and proteinuria were assessed. Close collaboration with the clinicians is urged, with the aim of applying immunosuppressive therapy immediately after P.E. to consolidate the results obtained.

Adolescent↗

Rearrangements and aberrant expression of the retinoic acid receptor alpha gene in acute promyelocytic leukemias.

Although acute promyelocytic leukemias (APLs) are consistently associated with a reciprocal chromosome 15;17 translocation, the gene(s) directly affected by the breakpoints have never been isolated. The chromosome 17 breakpoint maps to near the retinoic acid receptor alpha (RAR alpha) locus. Investigation of 20 APLs and a large series of other neoplastic patients and normal controls revealed RAR alpha gene rearrangements and aberrant transcripts only in the APL cases. These findings suggest that the RAR alpha gene is involved in the APL chromosome 17 breakpoint, is implicated in leukemogenesis, and could be used as a marker for identifying leukemic promyelocytes.

Blotting, Northern↗

ABL proteins in Philadelphia-positive acute leukaemias and chronic myelogenous leukaemia blast crises.

The Philadelphia chromosome (Ph1) is present in 95% of chronic myelogenous leukaemias (CML) and 15% of acute lymphoblastic leukaemias (ALL). This cytogenetic marker is due to a t(9;22) translocation, which causes a rearrangement of the ABL oncogene. In order to better define the relationship between type of genomic rearrangement, variant ABL protein expressed and haematological phenotype, a series of Ph1-positive acute leukaemias, both myeloblastic (AML) and lymphoblastic, and several CML lymphoid blast crises have been analysed at the DNA and protein level. The results confirm the presence of the ABL protein P210 in all cases of CML, ALL and AML positive for rearrangement in the bcr region of chromosome 22, and, surprisingly, in one AML case apparently negative for bcr rearrangement. The ABL protein P190 was found to be present only in cases of ALL negative for bcr rearrangement. Polymerase chain reaction (PCR) analysis of the types of 9/22 junctions present in the mRNA of CML lymphoid blast crises showed no evidence of 'ALL-type' transcripts.

Adult↗

Mapping of chromosome 17 breakpoints in acute myeloid leukemias.

The 17q11-21 chromosomal region is frequently involved in non-random structural rearrangements associated with the M1 and M2 subtypes of acute myeloid leukemias (AML), as well as with the 15;17 translocation typical of the promyelocytic subtype. A number of genes have been localized in this region including the c-erbA-1 and c-erbB-2 proto-oncogenes, the genes coding for the granulocyte-colony stimulating factor (G-CSF), the retinoic acid receptor alpha (RAR alpha) and the myeloperoxidase enzyme (MPO). However, the precise location of these genes in relationship to the 17q11-21 breakpoint(s) has not been determined. Using in situ hybridization on metaphase chromosomes, we established the position of the breakpoints in relationship to the c-erbA-1, c-erbB-2, G-CSF, RAR alpha and MPO loci in a series of AML cases bearing 17q11-21 rearrangements. We report: (i) that the respective position of the five genes is centromere - c-erbA-1 - G-CSF - c-erbB-2 - RAR alpha - MPO - telomere; (ii) that the breakpoints of the various AML subtypes are variably located between the centromere and c-erbB-2 in M1 and M2; (iii) that the breakpoints are consistently located between c-erbB-2 and RAR alpha/MPO in M3; and (iv) that the breakpoint on chromosome 17 in the 15;17 translocation is located on 17q21 and not on 17q11-12 as previously reported.

Acute Disease↗

Effects of plasma exchange (PE) in primary biliary cirrhosis (PBC). A pilot study.

Six patients were studied to evaluate the efficacy and safety of plasma exchange (PE) in the treatment of primary biliary cirrhosis (PBC). All patients were affected by PBC at stage III-IV and presented symptoms refractory to pharmacologic therapy. Patients underwent PE for a mean period of 40 weeks (range 10-88). A mean of 33 liters (range 17-64) of plasma per patients was removed. Patients reported less fatigue (4/6), pruritus (5/5), nausea (3/3), Sjogren's syndrome (2/6), and painful neuropathy (2/3). A reduction of xanthomata was noted in one of the three affected patients. Definitive improvement was seen in the patient with Raynaud's phenomenon. A significant reduction was noted for serum cholesterol and gammaglobulins. ALT, AST, gamma-GT, alkaline phosphatase, bilirubin, prothrombin activity, AMA titers were not affected by PE. All patients suffered some mild adverse effects during PE. Two patients (IV stage) developed late edema and ascites after 34 and 44 weeks of treatment. We conclude that PE can be considered effective chronic treatment for advanced symptomatic PBC refractory to pharmacological therapy.

Aged↗

Philadelphia-positive thrombocythemia with a complex translocation involving chromosomes 9, 15, and 22.

We report a case of Philadelphia chromosome (Ph) positive thrombocythemia with a complex translocation. G-banding analysis showed the predominant karyotype to be 46,XX,t(9;15;22). Southern blot analysis revealed a rearrangement within the breakpoint cluster region on chromosome 22 similar to findings in chronic myeloid leukemia. These data suggest the presence of a complex Ph translocation involving t(9;15;22)(q34.1 or q34.3;q26.1;q11 or q13).

Adult↗

Induction of proliferation of acute myeloblastic leukemia (AML) cells with hemopoietic growth factors.

Like their normal counterparts, leukemic blasts have recently been shown to respond to hemopoietic growth factors in both suspension culture and in semisolid media. In the present study, we have evaluated the proliferative response of 35 AML cases to colony-stimulating factors (CSFs) containing conditioned media derived from the human cell lines GCT, 5637, MO and MG U87, and to human recombinant IL-1 (rh-IL1), IL-3 (rhIL-3), GM-CSF (rhGM-CSF) and G-CSF (rhG-CSF). In the great majority of cases, an increase of 3H-thymidine (3H-TdR) uptake was obtained in response to at least one conditioned medium. The labeling index (LI) and the growth fraction (GF), evaluated in a restricted group of cases, were also increased by the growth factors, suggesting that they act by recruiting leukemic cells in cycle from the resting compartment. The ability of blast populations to form colonies was also studied. Conditioned media were found to induce or significantly increase the clonogenic capacity in 20 cases out of 22. The response of leukemic cells to human recombinant CSFs and rhIL-1, used alone or in combination, was also assayed. The results, in agreement with those obtained with conditioned media, show that each leukemic case displays a different pattern of response to CSFs, and that optimal growth conditions must be individually assessed. The possibility of increasing the fraction of cycling cells in AML populations may represent a way to render them more sensitive to cytostatic agents, with a view to new therapeutic strategies.

Adolescent↗