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Biomedical subjects

H H Peter

Publications and source records attributed to H H Peter.

At least 325 records · Page 18Linked to original sources
PubMed1975

Characterization of the mononuclear cell infiltrate in human malignant melanoma.

In the skin infiltrate of superficial spreading melanoma, non phagocytosing mononuclear cells (NPMC) represent a major cell component. The number of NPMCs decreases as a function of tumour progression. In addition, when an NPMC is in contact with a malignant melanocyte, the latter cell exhibits ultrastructural degenerative changes. In the blood of healthy donors and of melanoma patients, atypical mononuclear cells (AMC) can be identified. AMCs have been shown to participate in antibody-dependent cellular cytotoxicity (ADCC) reactions against melanoma cells in vitro. In this paper, it is reported that NPMCs and AMCs have in common their size, and some ultrastructural features such as indented nuclei, dispersed organelles, rough endoplasmic reticulum profiles and surface microvilli. The two cell types are negative for non-specific esterase. They also fail to react for peroxidase at either the light or the electron microscopic level. They do not adhere to glass. AMCs do not form spontaneous E rosettes, they have no surface IgG and they have no receptors for complement. However, they do form rosettes with EAIgG. On frozen sections firm binding of EAIgG has been seen on the skin infiltrate in three cases out of 10. It is concluded that NPMCs might react with tumour cells in vivo, in the same manner as do AMCs in vitro.

Cell Membrane↗
PubMed1975

[The diagnostic value of the 67gallium-scintigraphy in malignant melanoma (author's transl)].

In 24 melanoma patients body regions with suspicion of metastatic spread were scanned with 67Ga-Citrate. Twenty-two out of 28 melanoma metastases (79%) could be scintigraphically visualized. Falsely negative scans were particularly frequent with small, indurated skin metastases, whereas falsely positive scans were not observed in this study. By means of in vitro experiments it was shown that the uptake of 67Ga into a human melanoma cell line was temperature dependent and reached a maximal value at 37 degrees C after 2 hrs of incubation. Furthermore, it was found that under the same in vitro conditions our melanoma cells bound and released 67Ga differently from 51Cr. From the release studies it was concluded that 67Ga unlike 51Cr does not form a stabile intracellular complex with cell proteins.

Axilla↗
PubMed1975

Cell-mediate cytotoxicity in vitro of human lymphocytes against a tissue culture melanoma cell line (igr3).

Purified peripheral blood lymphocytes from 13 healthy donors, 6 melanoma patients and 1 halo nevus patient were tested for cytotoxic activity against an allogeneic melanoma cell line (IGR3) in, at least, one of the following assays: cell-mediated cytotoxicity (ADCC) and microcytotoxicity assays (ma). The lymphocytes were isolated by Ficoll-Triosil gradient centrifugation (fraction F) followed by removal of iron-phagocytosing and adherent cells (fraction FFF) and by subsequent passage through anti-IgG columns (fraction FFF-C). Leukocytes of each fraction were identified by different methods including morphology, rosette-formation, phagocytic activity, and membrane fluorescence. CMC activity paralled ADCC activity at a log lower level of sensitivity. In both assays lymphocytes of fractions F and FFF had the highest activity, whereas in fraction FFF-C cytotoxicity was strongly reduced. In all three lymphocyte fractions CMC and ADCC activity could be blocked by preincubation of the effector cells in aggregated IgG. Furthermore, depletion of E rosette-forming lymphocytes slightly increased ADCC and CMC activity, whereas depletion of EA and EAC rosette-forming lymphocytes strongly decreased it. Our results therefore indicate that in both CMC and ADCC assays, non-adherent, non-phagocytic Fc receptor-bearing lymphocytes ("K" cells) were the active cytotoxic cells. In MA, on the other hand, mononuclear phagocytes seemed to be the most active cell population. So far no significant difference was observed in CMC, ADCC, and MA between control persons and melanoma patients

Animals↗
PubMed1975

Humoral and cellular immune reactions 'in vitro' against allogeneic and autologous human melanoma cells.

Based on 51Cr release from an allogeneic human melanoma cell (M1) cell-mediated (CMC) and antibody-dependent cellular cytotoxicity (ADCC) were determined in twenty-eight melanoma patients, thirty-one healthy controls, ten patients with other tumours and eleven chronic lymphocytic leukaemia (CLL) patients. The results were related to simultaneously performed microcytotoxicity (MC) tests, HL-A typing, plasma membrane fluorescence and B:T cell ratios in the peripheral blood. Furthermore, lymphocytes from six melanoma patients were tested in CMC and ADCC assays against autologous tumour cells. The following results were obtained. (1) A large number of healthy controls possessed lymphocytes which readily lysed M1 target cells in CMC and MC assays. (2) CMC activity of lymphocytes from melanoma patients was generally lower than that of control lymphocytes and decreased further with progression of the disease. (3) CLL lymphocytes were virtually non-toxic for M1 cells, even at high aggressor:target cell ratios. (4) ADCC assays with a heterologous rabbit-anti-M1 serum showed generally higher isotope release than CMC assays; this was particularly pronounced in the melanoma group and in the group of patients with other tumours. (5) No tumour-specific blocking factor could be detected in melanoma sera, as judged by the capacity of the sera to block CMC activity. (6) No obvious correlation was found between the results obtained in short-term CMC and long-term MC assays. (7) T lymphocytes, as determined by E-rosette formation, were significantly diminished in melanoma patients. (8) The HL-A type of lymphocytes from normal donors and melanoma patients did not appear to be related to high or low activity in CMC and MC assays. (9) Preliminary results of 51Cr release tests with autologous melanoma cells were encouraging with respect to the correlation of the results to the clinical course of the disease.

Antibodies, Neoplasm↗
PubMed1972

Cell-mediated cytotoxicity during rejection and enhancement of allogeneic skin grafts in rats.

Cell-mediated cytotoxicity (CMC) in spleens and lymph nodes of allografted rats was determined by release of (51)Cr from labeled target cells incubated with aggressor lymphoid cells. CMC was first detected in grafted adult rats on day 5, peaked on days 7 and 8, and declined rapidly to background levels by days 9 to 11. In allografted neonates and in cyclophosphamide-treated or neonatally thymectomized adults CMC was a fraction of that observed in normal adult rats. Enhancing antibodies deferred in vivo peak activity of CMC in allografted neonates for 3-4 days, and blocked in vitro the action of aggressor lymphocytes by binding to target cells. Enhancing antibodies had no effect on the cytotoxicity of aggressor cells, but horse antibodies to rat thoracic duct cells inhibited in vitro CMC of aggressor cells.

Animals↗
PubMedDate not supplied

Effect of lipopolysaccharides, lipid A and interferon on the cell-mediated cytotoxicity of human leukocytes against K-562 tumor cells.

The effect of lipopolysaccharides (LPS), lipid A and interferon on cell-mediated cytotoxicity was investigated using 51Cr-labeled K-562 tumor cells as targets. As effectors, peripheral blood mononuclear cells from healthy blood donors were obtained by Ficoll gradient centrifugation: mononuclear phagocytes were eliminated by iron phagocytosis and plastic adherence. A T cell-enriched population was obtained by passing mononuclear phagocyte-depleted mononuclear cells through nylon wool columns. LPS and lipid A augmented cell-mediated cytotoxicity provided mononuclear phagocytes were present. Supernatants from LPS-treated mononuclear phagocytes and T cells enhanced mononuclear phagocyte-mediated cytotoxicity to a higher degree than LPS and lipid A alone. This finding suggests the participation of a lymphokine. In contrast, the interferon preparation increased the cell-mediated cytotoxicity both of mononuclear phagocyte-containing and of mononuclear phagocyte-depleted effectors. Here, the participation of natural killer cells as effectors is suggested.

Cell Line↗