Biomedical subjects
Publications and source records attributed to A Vecchi.
A model, employing murine L1210 leukemia to which the artificial determinant TNP was bound in vitro and an anti-DNP antibody-ricin A-chain conjugate, was used to explore the in vivo therapeutic potential of combined immunotoxin-chemotherapy treatment. Under conditions in which immunotoxin and chemotherapy as single therapies had only marginal therapeutic activity, their combined use was markedly effective.
The authors report the results obtained from the application of electron microscopy techniques to the cytology of fine-needle-aspirated samples of neoplastic lesions from various body sites. These results show that the tissue structure, which is usually lost during the squashing necessary for light microscopy cytology, is preserved when the samples are processed for ultrastructural analysis. Electron microscopy also allows a highly detailed study of the cell's inner structures. Thus, when this technique is applied, fine needle-aspirated samples can be regarded as actual microbiopsies. However, because of the high cost of ultrastructural techniques, we suggest that actual analysis be performed only in selected cases, whereas fixation and inclusion for electron microscopy could be done routinely.
Mouse strains with different susceptibility to aryl hydrocarbon hydroxylase (AHH) induction and with different levels and/or affinity for a specific cytosolic binding protein ("receptor") were used to investigate the immunosuppressive effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Humoral antibody production was strongly inhibited in C57Bl/6 and C3H/HeN mice (more susceptible strains) with very low, single doses of TCDD (1.2 micrograms/kg), while other strains (DBA/2 and AKR) required higher doses (at least 6 micrograms/kg) to be partially suppressed. Longer exposure (8 weeks) did not increase the sensitivity of DBA/2 mice. A good correlation between the degree of enzyme inducibility and immunosuppression was observed in studies with B6D2F1 mice and backcrosses. Similar results were obtained with 2,3,7,8-tetrachlorodibenzofuran (TCDF), the most powerful competitor for TCDD "receptor" in vitro and in vivo. TCDD immunotoxic effects appeared to be associated with the presence of a specific cytosolic binding protein which mediates AHH induction.
The aim of this study was to investigate the relation of apraxia to the sequential features of the motor task required and to the intra-hemispheric locus of lesion. A single movement and a multiple movement imitation test were given to 60 control patients and 60 left brain-damaged patients, among which patients with frontal and parietal lesion were identified, based on CT scan evidence. Both groups performed the tasks using the left limb. On either test left brain-damaged patients scored poorer than controls and parietal patients were significantly more impaired not only than controls, but also than frontal patients. Seventy five per cent of them performed lower than the poorest control patient. In comparison, the severity and the frequency of the motor deficit following frontal damage was much lower. In no case was there a significant difference between the discriminating power of the single movement test and of the sequence test. These findings suggest that the left parietal lobe has a leading role in motor planning and that the control it exerts over the motor cortex of the right hemisphere does not necessarily involve pathways running through the left premotor area.
Disease-free surgical lung specimens from 13 patients with neoplastic or infectious diseases and from three subjects with non-neoplastic, non-infectious pathology were mechanically disaggregated. Natural cytotoxicity was tested against 51Cr-labelled K562 target cells. Unseparated lung cells had little cytotoxicity against K562 cells. Removal of plastic and nylon-wool-adherent cells resulted in cell preparations (morphologically 80% lymphoid) with increased cytolytic activity against K562 but cytotoxicity levels were considerably lower than those of blood lymphocytes tested in parallel. Similar results were obtained when phagocytic adherent cells were removed with carbonyl iron. The NK-resistant murine TU5 and human Raji lines were not affected by lung effector cells. In vitro exposure to partially purified fibroblast interferon enhanced the cytotoxicity of unseparated or non-adherent lung cells. Thus, unlike in mouse pulmonary tissue, low levels of natural cytotoxic activity are associated with the humans lung.
The effect of single doses of TCDD (1.2, 6 or 30 gamma/kg) on several immune parameters has been investigated in young adult C57B1/6 mice. TCDD profoundly suppressed the primary and secondary humoral response to T-dependent (sheep erythrocytes, SRBC) and T-independent (Type III pneumococcal polysaccharide, S III) antigens. In vitro lymphoproliferative responses to Concanavallin A (Con A) and bacterial lypopolysaccharide (LPS), and macrophage and natural killer (NK) cell-mediated cytotoxicity were not significantly affected per unit number of lymphoid cells. Moreover, the ability of splenocytes from TCDD treated animals to mediate a graft versus host (GVH) reaction was not impaired.
The effect of single dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, 1.2, 6 or 30 micrograms/kg i.p.) on primary humoral antibody production was studied in young adult C57 BL/6J mice. TCDD profoundly suppressed the primary response to thymus-dependent (sheep erythrocytes) and independent (type III pneumococcal polysaccharide) antigens. The inhibitory effect of TCDD was still detectable 42 days after treatment. In contrast, under these experimental conditions, in vitro lymphoproliferative responses to Concanavalin A (Con A) and bacterial lypopolysaccharides and the ability to mediate graft versus host reaction were not significantly affected per unit number of lymphoid cells.
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Mononuclear phagocytes were isolated from the peripheral blood (PB) and ascites tumors of 35 patients with epithelial ovarian tumors. After 48 hours of incubation with the TU5 tumor, tumor-associated macrophages (TAM) and PB monocytes from cancer patients showed lower cytolytic activity than did control cells, but by 72 hours there was little difference between control and ovarian cancer effector cells. Primary ovarian carcinoma cultures were heterogeneous in their susceptibility to macrophage cytotoxicity. Tumor cells from 7 patients were significantly lysed by monocytes and macrophages, whereas four ovarian cancer cell preparations were resistant to cytotoxicity. A "feeding" effect of mononuclear phagocytes on non-lysable tumor cells was detected in terms of both lower [3H]thymidine-release values in the cytolysis assay and increased proliferation in cytostasis assays. Thus patients with ovarian carcinomatous ascites PB monocytes and TAM had impaired cytotoxicity against a tumor cell line, and primary ovarian carcinoma cultures were heterogeneous in their interaction with mononuclear phagocytes.
C57Bl/6 J mice (6-8 weeks old) were given single i. p. doses (1, 2, 6 and 30 micrograms/kg) of 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) and macrophage-mediated and natural killer (NK) cell-mediated cytotoxicity was evaluated at different times after treatment. Peritoneal macrophage cytolytic activity was measured as 3H-thymidine release from prelabelled mKSATU5 target cells in a 48 hours assay; macrophage-mediated cytostasis was assessed in terms of inhibitions of 3H-thymidine uptake by SL2 lymphoma cells. Spleen NK activity was measured using 51Cr-labelled YAC-1 lymphoma cells as targets. TCDD did not modify spontaneous macrophage-mediated and NK cell-mediated cytotoxicity per unit number of effector cells nor did it affect the macrophages' capacity to express increased cytolytic and cytostatic activity in the presence of endotoxin. Lower numbers of peritoneal macrophages and splenocytes were recovered from TCDD treated mice. Thus the total numbers of lytic units recovered from animals exposed to TCDD were lower than controls. Impairment of these cellular effector mechanisms, due to cell loss rather than inhibition of function, might play a role in the lowered resistance to bacterial infection of mice given TCDD and in the carcinogenic and cocarcinogenic activity of this chemical.
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Spleen natural killer (NK) activity was investigated in cells from C57BL/6J mice treated with various chemotherapeutic agents; 51Cr-labeled YAC-1 lymphoma cells were used as targets. Treatment with azathioprine (a single injection of 100-400 mg/kg ip or 5 daily doses of 80 mg/kg lp) and cyclophosphamide (a single injection of 50--200 mg/kg ip or 5 daily doses of 25 mg/kg ip) resulted in a marked dose-dependent inhibition of NK activity 2 days later. NK cells recovered rapidly from drug-induced suppression; by 7 days after drug treatment, no difference from control values was observed. Dimethyltriazenoimidazole carboxamide (20--200 mg/kg ip) and adriamycin (10--15 mg/kg iv) did not impair natural cytotoxicity per unit number of lymphoid cells, daunomycin (10 mg/kg iv) caused borderline impairment of NK acitivity, and N-trifluoroacetyl-adriamycin-14-valerate (80 mg/kg iv) markedly suppressed natural cytotoxicity. These results are discussed in light of the known effects of these agents on T-cells, B-cells, and K-cells and on hematopoietic histocompatibility-type reactions.
A comparative investigation of the antineoplastic activity of adriamycin and its derivative, N-trifluoroacetyladriamycin-14-valerate (AD 32), was conducted in murine tumor models employing different treatment schedules and injection routes. In all conditions tested, ie, ascitic and disseminated L1210 leukemia, ascitic LSTRA lymphoma, and advanced Lewis lung carcinoma, AD 32 was significantly more effective in terms of lifespan prolongation and induction of cures than optimal adriamycin treatments. As with adriamycin, AD 32 was ineffective on ic transplanted L1210 leukemia.
A preliminary characterization of the immunomodulatory activity of isoprinosine in mice was conducted in both normal and tumor-bearing mice. Under the experimental conditions employed, isoprinosine given ip and orally was found to possess some immunomodulatory capacity in various model systems. The compound appeared to preferentially influence T- but not B-cell responses; it did not apparently influence the functional capacity of macrophages, K cells, and NK cells.
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The effector arm of antibody-dependent cellular cytotoxicity (ADCC) was evaluated using 51Cr-labelled chicken erythrocytes as targets in BALB/c mice transplanted with the Moloney sarcoma virus-induced tumours T-MSV and MS2, and in C57BL/6 mice transplanted with the chemically induced FS6 sarcoma, Lewis lung carcinoma and B16 melanoma. Tumour-bearing animals showed higher levels of ADCC than normal mice, a stimulation confirmed in MS2-bearing mice, using SL2 lymphoma cells as targets in a cytostasis assay. ADCC effector-cell capacity was higher in animals transplanted with the immunogenic, spontaneously regressing T-MSV than in mice bearing the poorly immunogenic metastasizing MS2 sarcoma. The increased ADCC activity detectable in the spleen of tumour-bearing hosts was not abolished by removal of phagocytic-adherent cells.