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Biomedical subjects

L Ricci

Publications and source records attributed to L Ricci.

At least 73 records · Page 4Linked to original sources
PubMed1987

Adoptive immunity in mice challenged with L1210/DTIC clones.

New antigenic specificities, not detectable on parental cells, have been induced by many investigators in mouse lymphomas by treatment with the antitumor agent 5(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC). The antigens are transmissible, after withdrawal of the drug treatment, as an inheritable character. The mechanism of induction, the molecular nature, and the number of the new antigenic specificities have not been completely elucidated. Four clones from murine leukemia L1210 isolated and expanded in vitro were treated in vivo with DTIC and the new sublines were studied in detail. The four drug-treated sublines studied exhibited strong immunogenicity since they were rejected by syngeneic animals. Immunosuppressed animals challenged with 10(7) A/DTIC or P/DTIC cells were reciprocally protected by the adoptive transfer of spleen cells from donors that had rejected a lethal challenge of A/DTIC or P/DTIC clone. In a similar fashion, the adoptive transfer of spleen cells obtained from animals that had rejected the Q/DTIC or the R/DTIC clones protected immunosuppressed mice challenged with Q/DTIC or R/DTIC cells. No antitumor activity was observed in cross-protective schedules other than those indicated. It was been concluded that (a) the L1210 leukemia line does not have antigenic cells, (b) four DTIC-treated clone sublines were rejected by compatible hosts, and (c) two mutually exclusive sets of antigens were expressed in four antigenic clone sublines.

Animals↗
PubMed1987

Photodynamic therapy in vitro and in vivo with hematoporphyrin derivative and laser light.

Photodynamic therapy is currently under investigation as a new form of treatment for solid malignant tumors in animals and in humans. The method involves photosensitization of drugs and fluorescent dyes, such as hematoporphyrin derivative (Hpd), after preferential incorporation by neoplastic cells. In in vitro experiments laser light activation completely destroys Hpd-pretreated EL4 cells. Mice bearing MS-2 fibrosarcoma treated with Hpd and laser light survived indefinitely, in comparison with control animals that were untreated or treated only with Hpd or laser light. In mice bearing the highly metastatic tumors B16 melanoma and Lewis lung carcinoma (LLC) treated with Hpd and laser light delivered through a quartz fiber optic significantly prolonged the median survival time. This therapy was compared with surgical excision of primary tumors and, for superficial nonmetastatic neoplasma MS-2, the photodynamic therapy was more effective than surgery, while for metastatic tumors B16 and LLC, there was no significant difference between the two methodologies. However, phototherapy is much less traumatic to the animals.

Animals↗
PubMed1986

L1210/DTIC antigenic subline: studies at the clone level.

Treatment of murine tumors with the anti-tumor agent 5-(3,3 dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC) has resulted in the induction of antigenic specificities not found in parental cells. After the withdrawal of DTIC treatment, the antigenic sublines maintained the new properties indefinitely, as a heritable character although the mechanism of induction and the molecular nature of the new antigens are essentially unknown. Seven clones from the murine immunogenic leukemia L1210/DTIC were selected and studied in some detail. Three of the seven clones showed an increased immunogenicity in vivo since two clones (D5 and D7) were rejected by syngenic mice and one (D6) prolonged the life span for 3 weeks (untreated tumours killed the mice in 7 days). The seven clones and the L1210/DTIC were recognized and lysed by in vivo primed, in vitro stimulated (with L1210/DTIC) lymphocytes. Therefore, the seven clones shared antigens with the L1210-DTIC immunogenic subline. Secondary stimulated lymphocytes to clone D5, and clone D7 were able to lyse D5, D6 and D7 cells, respectively, but were unable to recognize the remaining clones. From in vivo and in vitro studies, all the L1210/DTIC sublines are composed of cells carrying two or more distinct antigens. Each cell clone expressed one set of antigens. It was concluded that only a few antigens expressed in different cells were induced by a DTIC treatment of L1210 leukemia.

Animals↗
PubMed1984

In vivo assimilation of low density lipoproteins by a fibrosarcoma tumour line in mice.

A tumour line inoculated in mice showed high affinity binding for lipoproteins in vitro. Studies in vivo demonstrated that the assimilation of human low density lipoprotein (LDL) by the tumour was very high. Both receptor and non-receptor mediated catabolism of the lipoprotein by the tumour increased as compared to other tissues known to be sites of lipoprotein catabolism (liver, spleen etc.). These findings suggest that lipoproteins may be useful markers for tumours as well as carriers for cytotoxic drugs to target tissues in vivo.

Animals↗
PubMed1984

Hematoporphyrin derivative rescue from toxicity caused by chemotherapy or radiation in a murine leukemia model (L1210).

Hematoporphyrin [1,3,5,8-tetramethyl-2,4-bis(hydroxyethyl)-porphin-6,7-dipropio nic acid dihydrochloride derivative] (HPD) is a compound that was studied in a number of laboratories because of its cytocidal activity after activation by light. Modification of immune function seen during the photochemotherapeutic studies prompted attempts to determine the effect of HPD on the immune and hemopoietic systems. Splenic hyperplasia as well as marrow hypercellularity were noted in mice treated with HPD. In vitro phytohemagglutinin or lipopolysaccharide stimulation of spleen lymphocytes caused normal or scant increases in blast transformation compared to the stimulation index for lymphocytes from untreated animals. HPD treatment did not significantly alter production of antibody to sheep red blood cells, as evaluated by hemagglutination or hemolytic assay. In contrast, HPD treatment did promote an increased number of spleen colonies in lethally irradiated mice transfused with syngeneic bone marrow. The capacity of HPD to increase the number of bone marrow and spleen cells has been exploited to accelerate the recovery from peripheral leukopenia induced in animals by previous drug or radiation treatment. The time for full return from severe leukopenia induced by an antimetabolite compound (5-fluorouracil) or an alkylating agent (cyclophosphamide or X-rays was significantly shorter in mice treated with HPD than in controls. Furthermore, improved survival was demonstrated in irradiated mice after HPD treatment. Finally, HPD treatment of L1210 leukemic mice did not affect the antitumor activity of cyclophosphamide. If the properties described here be confirmed, HPD might contribute to recovery of leukopenic cancer patients.

Animals↗
PubMed1983

[Possible applications of living BCG and the BCG cell wall in immunotherapy].

BCG, Bacillus Calmette-Guerin, has an immunostimulant capacity and antitumor activity against both experimental and human tumors. Its mechanism of action has not yet been well clarified; maybe it involves one or more immune cell populations: in fact BCG has been reported to loose its activity in immunosuppressed animals. A limiting factor for systemic use of living BCG is its high toxicity: therefore BCG-derivatives have been introduced in both the experimental and the clinical fields. For experimental use one of the most interesting of these products is BCG-cell wall: when used in laboratory animals it demonstrated an efficient dose-dependent antitumor activity and lack of toxicity. On the contrary living BCG was notably toxic and ineffective when used in high doses. An interesting approach in antineoplastic therapy is the use of BCG with tumor cells as a vaccine against micrometastases remaining after surgery, chemotherapy or radiotherapy. A vaccine containing BCG-cell wall and tumor cells (either living or x-irradiated) gave very encouraging experimental results for a possible clinical use in the treatment of tumor metastases.

BCG Vaccine↗
PubMed1983

In vitro hematoporphyrin (Hpd) inhibitory effects on some immunological assays.

Hematoporphyrin derivative (Hpd) is a fluorescent dye that is preferentially incorporated by tissues with a high mitotic index, such as tumor cells and blast cells. A cytotoxic effect is produced following light activation. Previous studies have shown a long lasting reversible inhibition of DNA synthesis in Hpd-treated cells that failed to stimulate allogeneic lymphocytes in either primary or in secondary MLR. In this study we report Hpd inhibitory effects on some immunological assays in vitro. Treatment with Hpd of cytotoxic effector cells resulted in inhibition of their lytic activity likely dependent on the loss of binding to target cells. In the same way Hpd treatment inactivated the lytic activity of NK cells. In contrast Hpd-treatment of target cells did not modify the above immunological reactions. Moreover Con A agglutinability, antibody dependent capping as well as E-rosettes were inhibited following an Hpd treatment of relevant cells. Since normal susceptibility to humoral and cell mediated lysis was exhibited by Hpd-treated cells it is unlikely that cell surface molecules were damaged. An inhibitory effect exerted by an Hpd treatment on cell surface movements might explain these findings.

Agglutination↗
PubMed1983

Hematoporphyrin derivative photoradiation therapy in murine solid tumors.

The cytocidal activity of light-activated hematoporphyrin derivative (Hpd) in experimental and human tumors is under investigation in many laboratories. This activity is based upon preferential incorporation of Hpd in malignant tissues and its photosensibilization by red light. Treatment of mice bearing MS-2 fibrosarcoma and B16 melanoma, a metastastic tumor, with Hpd and laser light, externally or delivered through a quartz fiber optic imbedded directly into the tumor, significantly prolonged the median survival time. This therapy was compared with surgical excision of primary tumors, and preliminary results on metastatic neoplasm suggest that the photoradiation therapy is more effective than surgery.

Animals↗
PubMed1981

[Lymphocyte populations and cerebrospinal fluid immunoglobulins in patients with polyradiculoneuritis. I].

We have studied four patients affected by poliradicoloneuro inflammation with rosette test ET - Ea and EAChu and with the dose of Ig cerebral fluid. The results of these experiments seems interesting in furnishing elements indicative of the immunological status of each patients. In fact, one can observe a significant increase of rosette Ea as a possible reaction or intervention of this subpopulation of T engaged in the immunitary response. We observed further that an increase of Ig neuro-fluid and, in particular, of IgG, could strengthen the idea of a probable humoral immunitary moviment as a result of poliradiconeuro inflammation.

Adolescent↗
PubMed1981

Longitudinal study of clinical, neurophysiological and immunological parameters in multiple sclerosis. Preliminary investigation.

Thirty subjects affected with multiple sclerosis, of which 22 were female and eight male, with an average of 30 +/- 7, years were studied, for a period of 10-15 months,. clinically using Kurtzkes' report form, neurophysiologically (responses tested: VEP, BAEP, SEP, ESG) and immunologically (Rosette Et, Ea, EAC). Of the 30 cases, 19 showed poussées in the last three years and 11 were in the stabilization phase. The Kurtzke reports and the neurophysiological tests permitted an accurate assessment of lesion levels and their rate of evolution. The immunological tests showed a notable ability to differentiate between subjects with recent poussées and those in the stabilization phase presenting overall values significantly below the norm. In the follow-up, after treatments with methisoprinol, the immunological tests also revealed modifications of notable interest.

Adult↗
PubMed1979

[Clinical and instrumental study program of nodular diseases of the thyroid].

Authors have passed from a combined clinical and radioisotopic analysis to an integrated polyinstrumental approach by adding thermography and above all echography. In order to achieve the purpose Authors have confronted in retrospective a "clinico-radioisotopic group" of 103 cases, from 1965 to 1975, and an "integrated polyinstrumental group" of 53 cases, since 1976. Comparing the "clinico-radioisotopic method" with "polyinstrumental approach" the main results could be summarized as follows: the diagnostic specificity improved in benign lesions from 77% to 96%, however in malignant lesions it remained about the same (63%). Considering these results the Authors have subdivided thyroid nodules, mainly based on echography, in two distinct categories with the following orientation: I. Solitary Thyroid Nodule: a) definitely cystic -- demonstrated by echography; b) "cold" -- by conventional scintygraphy; c) "negative" -- by thermography; d) non uptake of tumor seeking radiopharmaceutical. The control, therapy and surveilance of these cases should be limited to needle aspiration of the cystic cavity followed, of course, by citologic examination. This aspirations is both diagnostic and possibly therapeutic. II. Solitary Thyroid Nodule: a) definite solid -- echography; b) "cold" -- convential scintygraphy; c) "positive" --thermography (possibly "negative"); d) non uptake of tumor seeking radiopharmaceutical. Here the therapeutic orientation is clearly surgical.

Cysts↗