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Biomedical subjects

G Forni

Publications and source records attributed to G Forni.

At least 199 records · Page 11Linked to original sources

Induction of resistance or enhancement to a transplantable murine plasmacytoma by transfer of non-immune leucocytes.

Newborn mice have a lower spontaneous resistance to the growth of a syngeneic plasmacytoma (MOPC-460) as compared to adult mice. The transfer of different leucocyte populations from non-immunized adult donors to newborn mice influence in a dual way the resistance to MOPC-460 growth, depending on the number of cells transferred. The transfer of a low number of neutrophils, thymus or spleen cells enhances the MOPC-460 takes. Higher numbers of neutrophils, thymus or bone marrow cells induce an effective protenction. By contrast, macrophages over a dose of 1 X 10(4) constantly produce a reduction of tumour growth.

Animals↗

Mutant lines of guinea pig L2C leukemia. II. Comparative cytogenetic studies and banding analyses of normal and leukemic karyotypes.

Chromosomes of normal guinea pig (strain 2) cells and of cell lines dervied from a spontaneously arising leukemia were analyzed in detail. All cell lines studied, LG-L2C, GH-L2-C, BZ-LC, and EN-L2C, contained one M1 marker and two X chromosomes, in addition to other chromosome abnormalities specific for each cell line. The presence of the M1 marker and the two X chromosomes confirmed that all of these leukemic cell lines are derived from one ancestral line. Comparison of the chromosome markers and immunologic characteristics of these lines revealed that possibly the gene involved in the determination of C3 receptor sites is located on the terminal portion of the long arm of chromosome No. 2, but no other correlations could be made.

Animals↗

Heterologous sera: a target for in vitro cell-mediated cytotoxicity.

During the course of studies in inbred Strain 2 Guinea pigs on in vitro cell-mediated cytotoxicity to viral induced fibrosarcomas, it was observed that fetal calf serum in the medium in which the target cells were grown was responsible in some instances for much of the cytotoxicity observed. This fetal calf serum-specific cytotoxicity seemed mainly mediated by T cells and appeared to be independent on histocompatibility between target and killer cells.

Animals↗

Studies on Vaccinium myrtillus anthocyanosides. II. Aspects of anthocyanins pharmacokinetics in the rat.

Vaccinium myrtillus anthocyanins adminstered by i.v. or i.p. route to the rat undergo a rapid body distribution and in part also are easily eliminated such as to fit a three-compartments pharmacokinetic model. The anthocyanins elimination occurs mostly through urine and bile. The slight difference between the amount of anthocyanins eliminated after i.v. and after i.p. application shows a modest liver extracion of these substances. Vaccinium myrtillus anthocyanins possess a greater affinity for some tissues, namely kidneys and skin rather than for plasma. This fact could explain the long-lasting activity of anthocyanins on capillary resistance which is still elevated when plasma levels of these substances are no more detectable.

Animals↗

Inhibition of replication of virus-transformed fibroblasts by antibodies to RNA.

The activity of 7S immunoglobulins (Ig) antibody to RNA, obtained in rabbits after a prolonged immunization with RNA-methylated bovine serum albumin complex was evaluated in vitro on normal (3T3) and simian virus 40-transformed (SV 3T3) mouse fibroblasts. The presence of anti-RNA antibody in the culture medium inhibited both the SV 3T3 cell proliferation and the [3H]thymidine incorporation. In contrast, an increased [3H]uridine incorporation was evident within 48 and 96 hr of culture. No significant modification in these 3 parameters was observed in 3T3 cultures treated in the same manner. Both 3T3 and SV 3T3 showed cytoplasmic fluorescence when cultured in the presence of fluoresceinated anti-RNA Ig. However, with the indirect fluorescence technique anti-RNA Ig were detected in SV 3T3 cytoplasm only. These data suggest that anti-RNA Ig were taken up by both 3T3 and SV 3T3, but only in SV 3T3 did the anti-RNA Ig retain their antigenic properties and block cellular proliferation.

Antibodies↗

Antigenicity of carcinogen and viral induced sarcomas in inbred and random bred guinea pigs.

A tumor specific transplantation antigen (TSTA) has been detected in a methylcholanthrene (MCA) induced guinea pig tumor. It was possible to induce resistance to rechallenge with the tumor by immunization with irradiated cells in CFA. In contrast, the same technique failed to detect TSTA in two viral (Kirsten strain mouse sarcoma virus, Ki-MSV) induced guinea pig tumors; these results are similar to observations made with mouse Ki-MSV-induced tumors. Transplantation studies with these tumors in both inbred and random-bred guinea pigs showed a complexity of growth and rejection patterns. The B alloantigen, a major serologically defined antigen of the guinea pig histocompatibility complex, seemed to play a central role in acting as a guniea pig transplantation antigen. In all cases studied, the absence of B antigens in the recipient led to tumor rejection and anti-B antibody protection.

Animals↗

Evidence for a membrane carrier molecule common to embryonal and tumour-specific antigenic determinants expressed by a mouse transplantable tumour.

Rabbits were primed with membrane antigens solubilized from BALB/c embryo cells. After boosting with membrane antigens solubilized from a syngeneic transplantable adenocarcinoma, they developed a 'secondary' response against tumour-specific antigenic determinants. The antibodies against these determinants neither reacted with nor were absorbed by the antigens prepared from embryonal cells. However, the antigen displaying the tumour-specific determinants was bound by a reversed immunoadsorbent of insoluble anti-embryo antibodies. Indirect immunofluorescence experiments performed on adenocarcinoma cells in culture showed that, under conditions where redistribution of cell membrane components was induced, the anti-embryo antiserum aggregated the tumour-specific determinants. The purification of embryo and tumour-specific antigens achieved by affinity chromatography on insoluble antibody columns yielded three polypeptides of molecular weight close to 25,000, 20,000, and 10,000 Daltons respectively. It is suggested that the antigenic determinants responsible for tumour and embryo specificities in adenocarcinoma were located on the same molecule, or, more likely, on molecules which are closely associated in the plasma membrane and that do not dissociated in bile salts.

Adenocarcinoma↗

Growth of syngeneic tumours in unimmunized newborn and adult hosts.

The post-natal development of "natural" resistance of Balb/c mice to the challenge of syngeneic tumours was studied using injections of various doses of live neoplastic cells into untreated animals of increasing age, from neonatal to 12 weeks.The minimum quantity of neoplastic cells capable of inducing tumours increased in parallel with the age of the animals. Immunodepression with whole body irradiation with X-rays reduced the resistance offered by adult mice to tumour challenge to that of the neonate. The relationship of the increase in resistance to tumour challenge with the development of the animals' own immune response during the course of post-natal growth is discussed.

Adenocarcinoma↗

Interleukin-2 injected around tumor-draining lymph nodes in head and neck cancer.

Twenty patients with recurrent, inoperable head and neck squamous cell carcinoma received perilymphatic injections of natural interleukin-2 (nIL-2) for 10 days. Ten patients received 200 units (U) of nIL-2; five 1,000 U; and five 5,000 U. Irrespective of the location of the recurrence, the injections were always performed 1.5 cm below the insertion of the sternocleidomastoid muscle on the mastoid. When the ipsilateral lymphatic chain was still present, they were performed on the same side as the tumor site, whereas when it had been stripped as a result of previous surgery, they were contralateral. Patients who had undergone bilateral neck dissection were injected on the tumor side. Whenever possible, the treatment was repeated after 45-day intervals. In 13 patients (65%) with bilateral or contralateral lymph nodes, complete or partial disappearance of the lesion was observed. Despite these marked responses, the tumor always relapsed, and subsequent IL-2 courses were poorly effective. There were no systemic disturbances during or after treatment, but only moderate local swelling and pain.

Adult↗

Interferon-gamma plays a crucial role in T lymphocyte reaction against alloantigens.

In this study we report that addition to mixed lymphocyte reactions of monoclonal antibodies to interferon-gamma inhibits alloantigen recognition and induction of cytotoxic T lymphocytes by inducing early and highly effective suppressor T lymphocytes. This inhibitory activity is not confined to in vitro models, since daily local injection of these antibodies in CBA/J mice blocks the rejection of fully allogeneic tumor cells consistently displayed by untreated CBA/J mice.

Animals↗