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Biomedical subjects

A Vecchi

Publications and source records attributed to A Vecchi.

At least 73 records · Page 4Linked to original sources
PubMed1991

Incidence of lymphoid markers in acute myeloid leukemia. Alkaline phosphatase-antialkaline phosphatase versus immunofluorescence.

The aim of the present study was to compare the immunofluorescence technique (IF) with the immunoenzymatic (IE) alkaline phosphatase-antialkaline phosphatase method for the evaluation of the presence of lymphoid antigens (Ag) in 46 cases of acute myeloid leukemia (AML). The first technique allows detection of Ag expressed on the cytoplasmic membrane of living cells, whilst the second shows the presence of intracytoplasmic Ag on fixed cells. In general, the percentages of lymphoid Ag expression on AML cells are relatively low with both IE (15.2%) and IF (17.4%). We found a good correlation between the two methods for CD2 (4/4), CD7 (4/5), CD20 (1/1) and CD4 (2/2). The Ag CD19, CD21 and CD8 were negative in all cases, both with IE and with IF. CD3 (2 cases) and CD22 (1 case) were only evident with IE. CD10 was seen in 1 case with IF, whilst it was found more frequently with IE. For this reason, demonstration of CD10 with IF is more specific for the classification of acute leukemia.

Antigens, CD↗
PubMed1991

The use of the alkaline phosphatase-antialkaline phosphatase technique for immunophenotyping acute myeloid leukemia.

The leukemic cells from 31 cases of acute myeloid leukemia were immunophenotyped by the alkaline phosphatase-antialkaline phosphatase (APAAP) technique, using 7 monoclonal antibodies reactive with cells of myeloid origin. We found a good correlation between the results obtained using the APAAP method and indirect immunofluorescence. In most cases, we observed a slight degree of variation in the percentages of reacting cells when comparing the two methods. Nevertheless, taking 20% of cells being immunolabeled as a threshold for defining a case as positive, we found no discrepancies in the final classification of each case. The main advantages of the APAAP method are: (1) its use with routinely prepared peripheral or blood marrow samples, and (2) the possibility of correlating immunological characterization with morphology. Since the results with the APAAP method were comparable with those obtained using indirect immunofluorescence, we suggest that this former technique can complement, and sometimes substitute, other methods of immunological evaluation.

Alkaline Phosphatase↗
PubMed1991

Impairment of cytokine production in mice fed a vitamin D3-deficient diet.

C57Bl/6 female mice fed a Vitamin D (VIT-D)-deficient diet had serum levels of 25-hydroxyvitamin D decreasing with the time of diet exposure (3 and 8 weeks). Cytokine production (IL-6, TNF and IL-1) by peritoneal macrophages cultured in vitro with a standard stimulus, LPS, evaluated in the supernatants as biological activity, was significantly reduced in VIT-D-deficient animals. The defect in monokine production was partial and was evident at suboptimal LPS concentrations and incubation times. I-A antigen expression, induced in macrophages by in vitro exposure to IFN-gamma, was not modified in VIT-D-deficient mice, but IFN-gamma-inducible macrophage cytotoxicity to tumour target cells was significantly decreased in VIT-D-deficient animals. Moreover, basal and Poly I:C-induced NK activity was not modified by VIT-D deficiency. Thus, macrophage functions, such as cytokine production and tumour cytotoxicity induction, are down-modulated in vitro by VIT-D deprivation. To give more support to the relevance of VIT-D availability for cytokine production, TNF and IL-6 have been evaluated in the sera of control and VIT-D-deficient mice given LPS as a model stimulus. Serum peak levels of both cytokines were at least halved in VIT-D-deprived mice. Thus, VIT-D deficiency may represent a model of partial defect of monokine production.

Animals↗
PubMed1990

3-Methylcholanthrene induces differential inhibition of humoral and cell mediated immune responses in mice of different ages.

C57B1/6 mice aged 2-3 and 13-14 months were treated i.p. with 3-methylcholanthrene. A single dose of 25 mg/kg reduced primary antibody production to the T-dependent antigen sheep red blood cells by 20% in mice aged 2-3 months and by 90% in 13-14-month-old animals. The same treatment did not reduce antibody production to the T-independent antigen pneumococcal polysaccharide type III in young mice, but reduced this response by 50% in 13-14-month-old animals. Blastogenesis to concanavalin A, phytohemagglutinin and alloantigens, that is mediated by T lymphocytes, was consistently reduced in young animals but only marginally affected, when at all, in 13-14-month-old mice. Blastogenesis to lipopolysaccharide, mediated by B lymphocytes, was reduced in mice of both ages, though in older mice it was affected later than in younger animals. Addition of 3-methylcholanthrene in vitro increased T lymphocyte responses equally in mice of both ages and did not modify B lymphocyte proliferation. Results presented here show that older mice are not necessarily more susceptible to all types of immunosuppression induced by a xenobiotic like 3-methylcholanthrene and that the sensitivity of the different facets of the immune response can change with aging.

Age Factors↗
PubMed1990

Fine needle aspiration biopsy of the prostate gland: our experience concerning 101 cases with histological follow-up.

Our experience concerning 605 fine needle aspiration (FNA) biopsies performed between 1985 and 1988 is reported. FNA specimens of the prostate gland were compared to histological material in 101 cases: 37 patients underwent suprapubic prostatectomy, 15 radical prostatectomy, 28 transurethral resection, and 21 core needle biopsies. Adenocarcinoma was correctly diagnosed by using cytology in 39 out of 40 cases; benign prostatic hypertrophy was confirmed by histology in 54 out of 57 cytologically benign cases. The absolute sensitivity of the FNA biopsy was 98.2%; specificity was 98.1%; efficiency was 96%; and false negative rate was 6.6%. Our data support the value of transrectal aspiration biopsy as a precise and easy method for diagnosing prostatic cancer; the low false negative rate and the high number of correct diagnoses underline the great accuracy of the method.

Adenocarcinoma↗
PubMed1990

Sinus histiocytosis with massive lymphadenopathy: immunological, cytogenetic and molecular studies.

We describe a case of "sinus histiocytosis with massive lymphadenopathy" (SHML) studied by immunohistochemical, cytogenetic and molecular analysis. The immunophenotyping showed that the lymph node histiocytes were strongly positive for the S-100 protein and MoAb LeuM3, OKM5, KP1 and DRC-1; a portion of these cells was also positive for OKT6 and Leu3A, suggesting a possible relationship with the veiled cells, which represent an intermediate step in the pathway from the Langerhans cell to the interdigitating reticulum cell. Cytogenetic analysis showed a normal prevalent clone and a small hypodiploid clone and the molecular study showed no detectable involvement of the c-fms proto-oncogene, which is related to monocyte/macrophages. Unfortunately all these data do not seem sufficient to define the benign or neoplastic nature of the disease. Further investigations, immunophenotypical, cytogenetic and molecular, are needed to elucidate the pathogenesis of the disease, especially for more aggressive cases or for cases with unfavorable evolution.

Blotting, Southern↗
PubMed1990

In vivo effects of cyclosporin A on murine B-cells responding to type III pneumococcal polysaccharide.

The effect of cyclosporin A (CSA) on the antibody response to pneumococcal polysaccharide type III (a T-independent class 2 antigen) was investigated in mice. A single oral CSA administration (50 mg/kg) was able to depress (40%) the primary antibody response evaluated as spleen plaque-forming cells. Repeated treatments (12-50 mg/kg x 5) resulted in a higher degree of inhibition (80%) of anti-SIII response. Both single and repeated CSA treatments were active only when administered concomitantly with or after immunization, whereas no effects were seen with drug pretreatment. Comparable inhibitions of anti-SIII response were observed in control and nude mice suggesting a direct effect of CSA on B-cells.

Administration, Oral↗
PubMed1990

Extramedullary pleural blast crisis in chronic myelogenous leukemia: cytogenetic and molecular study.

Two patients with Ph1-positive chronic myelogenous leukemia with pleural blastic transformation occurring before medullary involvement are presented. The clonal origin of the pleural cells identified as unclassified blasts in 1 patient and as erythroid blasts in the other was confirmed by the presence of the t(9;22) translocation and their clonal evolution by the presence of duplicated Ph1 and additional chromosome alterations. DNA obtained from the pleural blasts and peripheral blood cells of 1 patient showed an identically rearranged bcr configuration, indicating the origin of the pleural blasts from the CML clone and suggesting that this genomic event is not directly linked with the progression of disease.

Aged↗
PubMed1989

IL-1 stimulates IL-6 production in endothelial cells.

Leukocytes and vascular cells interact closely in inflammation and immunity and lymphokines are important mediators of this interaction. The present study was designed to define the possible role of IL-6 as a communication signal between vascular and immunocompetent cells. IL-6 was measured as hybridoma growth factor (HGF) on the 7TD1 cell line in the supernatants of human endothelial cells (HEC). HEC released appreciable levels of HGF activity in the absence of deliberate stimulation. In vitro exposure to recombinant IL-1 beta markedly increased (usually 10 to 15-fold) HGF production by HEC. Optimal stimulation was observed with 0.1 to 50 U/ml for 4 to 20 h of incubation. Human and murine rIL-1 alpha stimulated HGF production in HEC. Anti-IL-6 antibodies inhibited the HGF activity of the HEC supernatants, thus confirming, together with the cytokine specificity of the assay, the nature of HEC-produced cytokine. IL-1-treated HEC expressed high levels of IL-6 mRNA as detected by Northern blot analysis. Inasmuch as IL-1 elicits a complex series of changes in HEC, it was important to assess whether IL-6, produced after exposure to IL-1, modified HEC function. Natural or rIL-6 did not affect the functional status of HEC as assessed by proliferative capacity, production of procoagulant activity and prostacyclin, ability to induce adhesion of polymorphonuclear leukocytes. The capacity to produce IL-6 may represent an important mechanism by which endothelial cells participate in inflammatory and immune reactions.

Blood Coagulation Factors↗
PubMed1988

Modulation by suramin of NK and monocytic cell-mediated cytotoxicity in human and murine cells.

The in vitro effects of suramin, a compound recently tested in AIDS treatment, were investigated on human and murine NK and monocyte macrophage cytotoxicity and monocyte migratory ability. In a short-term, TNF-dependent assay, pre-exposure (4-18 h) to 100-400 micrograms/ml suramin was associated with a markedly increased cytotoxicity by human monocytes and murine-elicited peritoneal macrophages, paralleled by a greater cytotoxic capacity in the supernates of these effectors. Preincubation with the same pharmacological suramin concentrations also resulted in enhanced spontaneous and directed migration in monocytic cells. Suramin-preincubated human PBL and murine splenocytes were unchanged in their basal NK cytotoxicity but exhibited a deficient response to IFN. Pre- and post-incubations with suramin resulted in increased macrophagic cytotoxicity for TNF-insensitive targets. Conversely, postincubation of effectors with the drug at 100-400 micrograms/ml was associated with profound decreases in both NK and TNF-mediated macrophagic cytotoxicities, and prior exposure to suramin of macrophagic supernates resulted in reduced cytotoxic activity. The mechanisms involved in the complex modulatory activity of suramin for monocyte macrophages and NK cells and the possible therapeutic implications of these findings are discussed.

Animals↗
PubMed1988

Preserved memory abilities in thalamic amnesia.

The pattern of preserved learning abilities is described in a severely amnesic patient after bilateral thalamic infarction. Experimental findings cannot be accounted for both by the view that only episodic memory is impaired in amnesia, while semantic memory is spared, and by the theory that what is spared in amnesia is procedural learning contrasted with impaired declarative memory. In agreement with Warrington and Weiskrantz (1982), diencephalic amnesia is considered to be a disconnection syndrome between the frontal and temporal lobes. The conditions for showing spared and impaired memory in amnesics are specified on the basis of the performance of the patient and of the data available in the literature. This allows us to derive practical suggestions for programmes aimed at remediation of memory defects.

Adult↗
PubMed1987

Effect of thymostimulin in models of cell-mediated and humoral autoreactivity and on T-dependent suppression.

To explore the therapeutic potential of the thymic hormone preparation thymostimulin (TS) in animal models of cell-mediated and humoral autoimmunity, its effects were investigated on experimental allergic encephalomyelitis in guinea pigs and on anti-erythrocytic autoantibody production in C57B1/6 mice. In both autoimmunity models, TS produced significant therapeutic effects in terms of proportion of diseased animals, disease severity and/or disease duration; however, both the TS dose and the time of treatment start relative to the disease-inducing stimulus critically influenced results. TS effects on the generation and expression of suppressive activity induced in C57B1/6 mice by a supraoptimal immunization with 10(10) SRBC were also examined. TS given after 10(10) SRBC did not influence the level of suppression, and the activity of effectors of suppression was not modified by this agent. Conversely, using a treatment protocol analogous to that effective in reducing murine autoantibody production, TS administration prior to 10(10) SRBC was associated with a significant increase in the subsequent generation of T-dependent, antigen-specific suppressive activity. These findings suggest that effects of TS on the development of suppressor cells may be involved in the activity of this agent in animal models of autoaggression.

Animals↗
PubMed1986

Interferon-activated tumor inhibition in vivo. Small amounts of interferon-gamma inhibit tumor growth by eliciting host systemic immunoreactivity.

Ten international units (IU) of recombinant (r) or natural (n) murine interferon (MuIFN)-gamma were used for the in vivo immunotherapy of a chemically induced fibrosarcoma (CE-2) of BALB/c mice. In vitro, doses of r-IFN-gamma below 100 units have a marginal antiproliferative effect on CE-2 cells and do not induce expression of H-2d class-II antigens, whereas they do increase that of class-I antigens. In vivo, 10 daily injections of 10 IU of r- or n-MuIFN-gamma at the challenge site provide significant protection against increasing doses of CE-2 tumor cells. This protection was enhanced when non-reactive T-lymphocytes from CE-2 tumor-bearing mice were admixed at a 10:1 ratio with the CE-2 tumor cells. Combined lymphocyte and r-MuIFN-gamma treatment also inhibited the growth of already established tumors when it was started before these reached a mean diameter of 5 mm. Tumor inhibition depends upon activation of the host immune system. The antitumor activity of r-MuIFN-gamma and T-lymphocytes was null when mice were first irradiated with 450 rads. Moreover, host leukocytes massively infiltrated the area of tumor growth and the small r-MuIFN-gamma doses injected daily activated various host immunoreactivity mechanisms.

Animals↗
PubMed1986

A preliminary analysis of the effects of elliptinium on immune reactivities in mice.

The immune effects of Elliptinium (2-methyl-9-hydroxyellipticinium, 9-HME), a chemical recently shown to possess clinical antineoplastic activity, were investigated in mice. Primary antibody responses to T-dependent and T-independent antigens, DTH reactivity and responsiveness to mitogens were significantly depressed only by post treatment with single drug doses of at least 5 mg/kg i.v., i.e. doses clearly above those known to exert full antitumoral effectiveness and to induce lymphoid cell depletion in the same species. Only drug doses in the LD50 range (i.e. 10 mg/kg) reduced the capacity of NK cells and of activated macrophages to express non-specific cytotoxicity towards tumor target cells. When repeated dose regimens were used, significant immune depression was again seen at doses above those displaying chemotherapeutic activity. Data obtained suggest that at chemotherapeutically effective dosages 9-HME possesses in mice a comparatively low immunodepressive potential and that immune cells mediating natural host defence mechanisms appear especially resistant to this drug.

Alkaloids↗
PubMed1985

[Anti-tetanus protection in a homogeneous group of vaccinated subjects from the city of Reggio Emilia].

The AA. have determined the antibodies against tetanus toxin of 739 young people that in 1968 underwent the first vaccination (passive haemagglutination test). 570 subjects (77.13%) entirely immunized and other 129 partially immunized turned out. Whereas the antibodies level of many examined subjects after fifteen years from vaccination was protective, the AA. suggest as correct a vaccination schedule with a dose every ten years to preserve the immunity.

Adolescent↗